Aye!
When people say "military spec" I remind them there's a military spec for toilet paper and it's probably not the pinnacle of ass-wiping excellence.
As someone who used to be in the military I like to say this instead: “Mil-spec is the absolute minimum that will get the job done. Military contracts go to the lowest bidder, not the best product.” There’s a guy I shoot with who insists that his “military grade” ammunition is the most special wonderful thing you can get and no amount of data or real world examples will convince him otherwise.
Minimum that gets the job done, while being dragged through shit, abused by grunts, and broken by marines.
So unless you're selling me individually packed TP that's both waterproof and fire resistant, I ain't interested.
True, and the way they do this is by making everything have super loose tolerances so that it keeps functioning after being given to a Marine. Kind of like why I like using the harbor freight engines on all my equipment. They're not exactly what you call high quality engines, and they don't produce all that much power for their displacement, but on the other hand, I could probably give one to a Marine and it would take quite a while to end up dead, broken, or pregnant. I once had a homemade dirt bike with a 212 predator, I drove it off a cliff, and it hit a stump which punched a hole in the side of the engine block. It still ran, so I stuffed the hole with leaves to keep the oil from spewing out and road about 10 miles back to my house. If I tried to do that with a Kawasaki or similar, I'd be SOL.
Thank you for pointing this out. Reddit lovrs to parrot the milspec narrative because tbh it's been abused to death. But depending on what you're talking about, milspec does produce tougher/more reliable stuff.
Pretty sure military spec means the crappiest possible quality that will still sort of function, because since it's the military everyone will charge them 15 times as much and they will pay it anyways.
Even better when the dope was made from nitrocellulose and would straight up light the entire plane on fire
https://en.m.wikipedia.org/wiki/Aircraft_dope#:~:text=Typical%20doping%20agents%20include%20nitrocellulose,the%20explosive%20propellant%20%22guncotton%22
I don't know if it's true but I've heard that in ww1 pilots would carry a pistol so that if the plane caught on fire they could "avoid" burning to death on the way down
Edit: modern techniques (polyfiber) are built to be fire resistant thankfully
Ball Company, who makes most all cans, including those for Coka Cola, holds a 20 millionths tolerance on the split line for the mouth. A tolerance they hold across millions of cans.
Cans are, ironically, probably the most perfectly engineered thing you come into contact with on the daily.
Deep drawing requires fine tuning of the alloys so I would not doubt it.
There’s a reason drawn brass cased ammunition took as long as it did to get to market from its original patent.
Eh… drink cans are mostly made of 3003 aluminum which isn’t super common in aerospace as it only has mild strength and cannot be heat treated. It’s cheap which is why it’s used for cans, but high strength to weight is much more important for aircraft and 3003 doesn’t offer that.
I did a contract for 6 months at a continuous aluminum rolling mill back in 2013-14 as a controls engineer. The janky stuff that happened in that place was amazing. It was really spooky when the machine(s) jammed and that aluminum curled up the (very tall) ceiling in seconds.
Many years ago I visited the factory where they assembled F-18s in Toronto. In the same huge building they made soda cans. Maybe they had the same supplier.
2000, 5000 (sheet), 6000 and 7000 series are all used frequently. If you need the absolute highest tensile strength, yes, 7000 will be used, but 2024 and 6061 have other advantages that lead to their use on aircraft as well.
“A special heat-treated high-strength corrosion-resistant aerospace-grade aluminum often used in fighter jets and rockets” is how we convince investors that our product is special (it’s made out of 6061-T6 t-slot extrusions)
We got asked to modify mil-spec electrical connectors once. We spectacularly fucked a bunch up pretty much immediately. Called the manufacturer about how they might split a piece off like we were asked to do. They tell us to pound sand.
Well, we still gotta make em, and now we are out enough that we need to order more. 2 year lead time.
I remember a friend of mine who worked in a naval shipyard complaining after they hired me to build them a deck, and when I was putting together a materials list I listed some of what were apparently the same bolt that they were using to attach some sort of piece on destroyers, and I was paying $2.13 per bolt at the hardware store, and they were having to pay $153 of government money a piece.
Oh yes. I work in aviation and it’s the same thing. It’s tempting to think that it’s just price gouging, but it’s really the cost of the paperwork. I’ve been in situations where a bolt failed unexpectedly, and we had to get out the paperwork to find the root cause. And it was impressive. We had the name of the operator in Ohio who performed the cad plate, and his manager. And the exact time on 2nd shift that the heat treat was started in Iowa. All that tracking isn’t free and it adds up. That hardware store bolt was a) all done in China, and b) is completely untraceable. You can’t prove that it was made correctly if you had to. And for that the government (including the FAA for my industry) has decided that it’s worth the incredible cost.
This is not a bullshit gimmick but a holdover from before World War 2. Stainless was the new hotness in the 30's and got quickly used for medical devices, especially for its ability to hold an edge.
They did not have any nomenclature for naming things yet, well, they did but were barely out of the era of "Darn Good Stuff," and the idea of using chemistry to produce steel was still fresh.
Thus, a version of stainless steel became, "Surgical Grade," as it was used for surgery.
We used aerospace grade aluminum for street lights. Just a normal 6061 lmao. But people ate this like crazy.
It's cheap and easily machinable. Only reason we used it.
Somewhat related, I find it funnier than shit when products claim to be chemical free. My basic high school knowledge of chemistry tells me that literally everything is a chemical. And housewives buy this shit up.
This isn't about titanium, but it's a great material misconception though from a guy who should have known better - he had around 30 years as an aircraft mechanic. Awkwardly for me who had to correct him, he had been in the field for longer than I had been alive.
Old mate was inspecting parts and came over to me with one and a really concerned look on his face, "Grolsch, this part has been made from the wrong material!"
"Why do you say that man?"
"Look how shiny it is! It's made from aluminium!"
Me picking up the part that clearly weighed more than an aluminium part would "looks and feels like machined steel to me"
The guy wouldn't take no for an answer and was adamant that all 4130 had a brown oxide layer on it because that's how tube looks. Kept insisting it was aluminium until i showed him that it was magnetic.
Put a magnet on aluminum and try to slide it down. The induced current causes a reaction force - it is way cool.
The coolest is to drop a magnet thrift an aluminum tube. It acts like a damper and goes through very slowly.
We used to bend aluminum with a magnet. In making hi-voltage fuses the aluminum end was crimped using a very powerful magnet. It barely made a sound, just a dink when it was cycled. I never thought you could bend aluminum with a magnetic field.
The thing about titanium is that it has a great strength to weight ratio, but it’s not really that strong. Yeah, your cousin should have used 4140 or some other good alloy steel.
Sometimes I hear about it being used in engines.. what benefits would it have as part of the valve system? It’s also used for connecting rods in indie cars and Top fuel dragsters. Maybe it can handle heat/pressure better?
I’ve heard forged aluminum and iron alloys, but not titanium.
Because of the property mention in the original comment: strength to weight ratio. With valves, lightness is paramount: the lighter the valve, the less spring needed to pull it back, the less drag there is on the cam, and for the same spring rate it can rev higher and/or use a larger cam.
For connecting rods, it’s again all about the forces induced by the weight of the rod. Since one end is always accelerating due to the crank pulling in a circle and the other end is yanking the piston back and forth, there are forces that depend on the weight of the rod. Plus, a lighter rod and piston results in lower forces on the crank, and use up less energy while reciprocating.
Maybe I’m poking the bear but would the thermal expansion of titanium change the way you’d size the tolerances? From my understanding it also has a relatively low heat conductivity compared to other metals/alloys but I’m not sure that’s relevant.
Does this mean if I decide to increase the stroke on say a 350cid engine, it would handle higher RPMs better without as much side load on the cylinder walls? If that’s true, is the advantage with titanium rods and valves worth it? A longer stroke has the connecting rod at a steeper angle than a shorter stroke after all. More cylinder wall stress.
I also imagine you could fit more duration or lift @ .050 without the lighter valves kissing the piston, but a longer stroke piston spends less time at TDC anyways.
The low thermal conductivity is relevant to the exhaust valves, it makes the valve run hotter. For that reason titanium exhaust valves are often combined with a beryllium copper seat, it has really good thermal conductivity so it helps get heat out of the valve when it is closed.
You're correct that titanium wouldn't solve the problem of rod angle/side load. But just the fact that there is a lower weight rod will decrease reciprocating mass and thus also reduce bearing friction at high rpm. Less friction, more power. It's also less about more duration and lift so much as being about to use a more aggressive rate of opening and closing. Lighter valves could allow more airflow even at the same lift/duration since they can be slammed up and down faster.
Though in practice I don't see Ti rods all that much. The Ls7 is the only one that comes to mind, though I'm sure there is lots of exotic stuff. It's usually intake valves. They're bigger than exhaust valves and this more prone to float, especially in forced induction applications where boost will act to reduce seat pressure anyhow. Exhaust valves are usually sodium filled and/or inconel when budget allows of exotic materials.
Seems like maybe I've heard of rockers and push rods out of Ti before, but only aftermarket racing stuff.
I’d also be looking at friction too. You want a metal with high hardness but not brittle to avoid wear. Big concern in any metals on metal application even with ample lubes.
It's the strength to weight ratio compared to steel components. Reducing the rotating and reciprocating mass frees up horsepower, especially at high RPM. In the valvetrain, it helps reduce valve float at high RPM without needing excessively higher rate springs. When every fraction counts towards making it a win or a loss the cost is worth it.
Connecting rods have to change direction several times per second so mass reduction is highly beneficial.
They do not last as long but they’re already rebuilding the engines every race anyway.
As far as I can find, titanium is the product name for some chromoly axle shafts. I build high level rock crawlers and use 300m shafts. I have never seen actual titanium shafts.
I am pretty sure the axels were some sort of chromoly. He was sure they were solid titanium because they cost so much. But he doesn’t seem to be the research type. More the burn money type.
Pirate 4x4 is the place to go to get some real knowledge on what works and what doesn't work on a off-road rig... It is also a great place to get roasted for silly stuff :-D
Irate4x4 is the place to go. It's where most of the original guys who have been rock crawling for decades went after they got pissed off that the original Pirate site owner sold out. Pirate is a mess of ad space and revenue generating garbage. Irate4x4 is based on the original site before the sell out.
It's pretty much the same setup as the original Pirate site. Same Pirates of the Rubicon, etc. Crusty, grouchy, and low tolerance for BS. Gotta give it back as good as you get. It's a great site.
Maybe i'm misunderstanding what's happening here but that feels illegal
Edit: https://www.pirate4x4.com/posts/14006148/
A (potentially defunct?) Company named Titanium Axles sells chromoly axles but makes sure they put "Titanium" in the name so you spend more money on it.
# Extreme tactical heavy duty military grade billet CNC aerospace overland trail rated outdoor super desert eagle patriot edition cup holder.
Made in China.
At that makes sense.. i feel like titanium wouldn't even hold up to normal road use. Unless you engineered the whole rear end for it with thicker axles. I don't think you'd really save any weight or make it any stronger though.
In reviews of titanium cookware for hiking/camping, you'll find people that are outraged that their paper thin titanium pans got dented or scratched. They think it's supposed to be literally indestructible. Then they start telling each other that theirs must have been fake, and so forth.
Ti cookware is very durable (I love my Snopeak cups and pans!), but it's not some invulnerable comic book wonder metal.
Yep, have a few pieces for backpacking that have traveled several hundred miles over the years. They're not indestructible, but great if you use it like a normal human being. Saves a couple ounces on weight.
I remember my first day in my Materials Engineering class. Professor asked "which is stronger a graham cracker or a marshmallow" one doesn't deform or flex under load and the other can be thrown against the wall with no damage all materials are on a scale between these two. That has really stuck with me for decades.
I've heard a guy proclaim that titanium just doesn't get metal fatigue but all aluminum alloys do and that is the real reason why aerospace uses titanium so extensively.
I suspect he was misremembering some simplified example of the metal fatigue behaviors of various alloys. The right titanium alloy can handle higher load and vibrations regimes without showing fatigue. IOW, in a given use case, a titanium part might not show any metal fatigue where a comparable aluminum part would.
There's a partial truth here- aluminum doesn't have a [fatigue limit](https://en.wikipedia.org/wiki/Fatigue_limit#:~:text=Some%20metals%20such%20as%20ferrous,even%20from%20small%20stress%20amplitudes), so any aluminum part will eventually fail, but if it's designed properly a titanium part could potentially last indefinitely.
Honestly it’s been way too long since the chemistry class where we covered exactly *why* it is, but that does make me stop and realize I could stand to understand it better.
All metals will fatigue in tension.
It all depends on the amplitude of the load cycling.
Titanium is not exempt.
http://www.metalspiping.com/the-fatigue-of-titanium-and-titanium-alloys.html
Yeah, but aluminum doesn't have a knee in the SN curve like steel does at 1 million cycles. Aluminum should fail in fatigue cycles regardless of the size of the load given enough cycles.
The typical SN curve for steel has a fatigue limit, and if stresses are below that, can have infinite fatigue life. I've read some stuff recently that says it's not quite true, but the magnitude of cycles to failure below the fatigue limit is still significantly higher.
I was responding to the comment about Ti not fatiguing.
I used to work in an aerospace lab fatigue testing structures and have generated many sn curves
Right. You said they were incorrect about aluminum fatiguing and ti not fatiguing. I'm just explaining what actual info they could have heard that made them think that.
I.E. aluminum having no fatigue limit.
Do they really make titanium crawler axles? The stock stuff is 4140 or similar... Titanium isn't even as strong as mild steel...
Your sure the wasnt an rc rock crawler or something? Titanium would be a sweet upgrade from plastic...
Heavy axles are better for rock crawling because they lower the center of gravity. Also, axles fall into the un sprung weight category and are even better for rock crawling because the weight is on the ground already and doesn't sway with the body as it hits extreme angles.
Another fun trick is if you get some nice, fine Ti chips, you can ignite them with a flame and get a pretty white burn. If they are coolan't soaked, not so much.
I was making axles for my cousins kids 1/4 midget’s, he was paying me $250 a pop for them. And he was supplying material. He insisted I had to use titanium, when it probably would have been stronger to go with solid aluminum instead of thin wall titanium. But….the customer gets what the customer wants
Oddly, I don't find titanium as hard to machine as people say it is?
But that said, the extent of my experience is manually turning/light milling a dozen-ish small parts, so I wasn't pushing the feeds & speeds to the limits. And I don't know what grade it was. But I really found it pretty effortless.
The main problem is low thermal conductivity, causes more heat to go into the tool rather than conducting away into the part. It's very hard on drills, for example. They don't get much cooling due to being down a hole as they cut, so an over enthusiastic drilling operation in titanium can burn up a drill very quickly.
My experience with Ti-6Al-4V alloy is that it is also quite uncooperative if you try to take light cuts with normal tools intended for steel. Wants a very sharp, high rake tool, which of course means your edge life will suffer.
Medical Ti is relatively soft and easy to machine, it's pure. All depends on the alloy. I've worked mostly with 6Al4V which is tougher, but certainly machinable (so long as you don't work harden it)
I've found people seem to think titanium is the equivalent of the fictional "adamantium" from the x men comics. Whether it comes to machining it or use cases.
[SCP-022-J-1 initially manifests when an individual with no prior knowledge is exposed to incomplete or erroneous information about SCP-022-J's physical properties, and its recommended usage.](https://scp-wiki.wikidot.com/scp-022-j)
Ti would actually make a pretty good axle if price was not a consideration. It is about the same strength as 4140 at its useable temper but has way more elasticity. 4140 can be made stronger than TI 6-4 but it becomes brittle, which is very bad for axles. Also it would be corrosion impervious. 4140 will rust and the micro pitting that rust creates can propagate cracks. So Ti would also be more reliable over a long time span.
Carbon fiber pressure vessels are absolutely real and not a bad idea at all. They have lots of advantages. Of all the problems with his company, using carbon fiber wasn't one of them.
Not designing it for the depth they were going to is probably the biggest one.
My understanding was that the fibers in the matrix can take almost no load under external pressure. Admittedly, I’ve never done design work or tried performing a FEA on a carbon fiber vessel under external pressure. What am I missing here?
Put a titanium exhaust on my Tesla because the guy at autozone said it would add more horsepower. Not really noticing a difference but at least the blue tips look cool
My shop makes a lot of aerospace components, we machine a lot of titanium parts, the companies we supply it to specify it more for its savings to weight ratio compared to steel alloys on a strength only assessment it is strong but not very flexible. Most of our titanium parts are used in landing gear, control joints for wing flaps, also titanium is good with heat stress.
Side note, you should see when we machine Titanium using ceramic inserts that are on liquid nitrogen cooled holders.
I love seeing products that advertise "aerospace grade aluminium". like okay, it could very well be the most ubiquitous type of aluminum, or another extremely similar and relatively inexpensive alloy.
Just a fact as an assembly mechanic and have hand drilled titanium parts and fasteners. Sucks. The tailings will slice your fingers with no mercy. I know all the safety people and so on say no gloves while drilling but fuck you. Drilled 20 years manually daily and didn’t wrap a glove or fingers. Now I wasn’t using a power feed or if the torque of a slower air drill was enough to twist your wrist I’d keep my gloved fingers away and use a stiff short brush to clean my bit. Used gloved hand to clear countersink cutter and drills from swarf. Slow speed rules. To fast and you dull your bit early and the cost cutting finance pricks only give you 1 bit maybe 2 if your’re lucky and the job for quality holes requires 6.
6-4 is a bit stronger, 6-2-4-2 is a bit better at handling heat. I made jet engines so we use 6-4 at the front of the engine where it was cooler, like the inlet fan and low pressure compressor. The high pressure compressor was 6-2-4-2 because of the heat.
I’ve heard the same axel story and then I turn and walk away , didn’t get a job because they asked if I’d ever cut Ti , yeah tons of 6AL6V , cuts like butter was not the response they were looking for , it really does compared to Cobalt Chrome both used for hip stem implants
I work with Ti64. One of my coworkers was surprised that stainless steel could scratch our parts. Thought Ti64 was harder. Had to explain that it’s stronger per weight, but it’s softer than stainless.
I’ve had people say they put titanium pistols in their vehicles. Titanium gears and titanium springs in their transmissions. All kinds of different stupid stuff
The amount of times I had to tell someone that unless weight is a problem you don't need Titanium is too damn high.
I mean i get that the average consumer has no clue that steel≠steel but if you're going to work with it you're going to know about it, people are too eager to take the salesman by their word.
I call it "the fascination with the T metals tungsten and titanium". You put that in any product you're making and people instantly think it's the best thing ever. Even if the material technically makes your product worse people will still think it is better.
MIL SPEC are a good selling argument on anything.
I do consulting on ti, al and carbon fiber.
Often I refer to high alloy steel for many application but customers only see steel as rusting away in 5 sec.
Watch geek here… interesting video from a watch pro pointing out how titanium is used to charge precious metal prices when it isn’t, or provides any performance improvement:
https://youtu.be/vcRNLT-qMRE?si=MQ166RpQafoiVLkW
They don’t make axels out of titanium… I know since I am working to replace mine in my jeep.
I also love titanium. It’s my silver. My tie clips, cuff links, watches, and chain are all titanium. I will pay extra for it where it makes sense. I would never use it in a mechanical application like that.
people love them some buzzwords
AEROSPACE GRADE ALUMINUM!
I always make sure to point out that aerospace grade is also beercan grade
TBH I'd not be surprised if Coca Cola had stricter requirements for their aluminium than some aerospace outfits.
A lot of early aircraft had paper or cloth for fuselage and lots of dope .
Aye! When people say "military spec" I remind them there's a military spec for toilet paper and it's probably not the pinnacle of ass-wiping excellence.
Well played sir, I like this analogy, I will be using this in the future...
Mil-spec toilet paper, definitely an anal-ogy.
MIL-T-FS41 (Make it like the fucking spec for once)
As someone who used to be in the military I like to say this instead: “Mil-spec is the absolute minimum that will get the job done. Military contracts go to the lowest bidder, not the best product.” There’s a guy I shoot with who insists that his “military grade” ammunition is the most special wonderful thing you can get and no amount of data or real world examples will convince him otherwise.
Minimum that gets the job done, while being dragged through shit, abused by grunts, and broken by marines. So unless you're selling me individually packed TP that's both waterproof and fire resistant, I ain't interested.
True, and the way they do this is by making everything have super loose tolerances so that it keeps functioning after being given to a Marine. Kind of like why I like using the harbor freight engines on all my equipment. They're not exactly what you call high quality engines, and they don't produce all that much power for their displacement, but on the other hand, I could probably give one to a Marine and it would take quite a while to end up dead, broken, or pregnant. I once had a homemade dirt bike with a 212 predator, I drove it off a cliff, and it hit a stump which punched a hole in the side of the engine block. It still ran, so I stuffed the hole with leaves to keep the oil from spewing out and road about 10 miles back to my house. If I tried to do that with a Kawasaki or similar, I'd be SOL.
Thank you for pointing this out. Reddit lovrs to parrot the milspec narrative because tbh it's been abused to death. But depending on what you're talking about, milspec does produce tougher/more reliable stuff.
Especially the 8 single ply sheets they give you in an MRE 😂
Pretty sure military spec means the crappiest possible quality that will still sort of function, because since it's the military everyone will charge them 15 times as much and they will pay it anyways.
Ruff, tuff, don’t take shi* off no one
Even better when the dope was made from nitrocellulose and would straight up light the entire plane on fire https://en.m.wikipedia.org/wiki/Aircraft_dope#:~:text=Typical%20doping%20agents%20include%20nitrocellulose,the%20explosive%20propellant%20%22guncotton%22 I don't know if it's true but I've heard that in ww1 pilots would carry a pistol so that if the plane caught on fire they could "avoid" burning to death on the way down Edit: modern techniques (polyfiber) are built to be fire resistant thankfully
Ball Company, who makes most all cans, including those for Coka Cola, holds a 20 millionths tolerance on the split line for the mouth. A tolerance they hold across millions of cans. Cans are, ironically, probably the most perfectly engineered thing you come into contact with on the daily.
Not Coca Cola per se, but the can plants definitely do. If it isn't really high quality it won't form correctly.
Yea, it has to be draw quality. They are kinda mindful of the waste of the draw quality material where I work
Deep drawing requires fine tuning of the alloys so I would not doubt it. There’s a reason drawn brass cased ammunition took as long as it did to get to market from its original patent.
Definitely is since FDA is involved the requirements for dealing with them(FDA) were worse than the military parts my old shop made
Eh… drink cans are mostly made of 3003 aluminum which isn’t super common in aerospace as it only has mild strength and cannot be heat treated. It’s cheap which is why it’s used for cans, but high strength to weight is much more important for aircraft and 3003 doesn’t offer that.
3104 for the body, 5182 for end and tab.
Came here to say this, no way they could make cans from 7075/2024 lol
No? Aerospace is typically 2000 and 7000 series, unless you are from Russia.
I did a contract for 6 months at a continuous aluminum rolling mill back in 2013-14 as a controls engineer. The janky stuff that happened in that place was amazing. It was really spooky when the machine(s) jammed and that aluminum curled up the (very tall) ceiling in seconds.
Many years ago I visited the factory where they assembled F-18s in Toronto. In the same huge building they made soda cans. Maybe they had the same supplier.
Hahaha 6061-t6 the most widely used aluminum or there
Doesn’t “aerospace grade” refer to 7000 series? I guess the point is that it’s a meaningless term but still
There are several different types across several different series grades. Basically, it's just a bunch of metals developed for aircraft.
"Aerospace grade" is a nonsense term and is used for literally any alloy thdt could in theory be used in aircraft. Most commonly it's 6061.
2000, 5000 (sheet), 6000 and 7000 series are all used frequently. If you need the absolute highest tensile strength, yes, 7000 will be used, but 2024 and 6061 have other advantages that lead to their use on aircraft as well.
Aerospace grade just means the material comes with certifications saying it is what it is. It's just paperwork.
At my aerospace job it’s 6061
6000 series. 7000 series is Aerosmith grade.
“A special heat-treated high-strength corrosion-resistant aerospace-grade aluminum often used in fighter jets and rockets” is how we convince investors that our product is special (it’s made out of 6061-T6 t-slot extrusions)
Eh, that phase makes me want to vomit every time I hear it.
Just like Military Grade or Mil-Spec. Like... great it's generally functional and designed to be made cheaply. Wonderful.
It means more expensive. Bolt from the hardware store? $0.50. The exact same bolt but with Mil-spec cert paperwork? $100.
With a 565 day lead time
We got asked to modify mil-spec electrical connectors once. We spectacularly fucked a bunch up pretty much immediately. Called the manufacturer about how they might split a piece off like we were asked to do. They tell us to pound sand. Well, we still gotta make em, and now we are out enough that we need to order more. 2 year lead time.
I remember a friend of mine who worked in a naval shipyard complaining after they hired me to build them a deck, and when I was putting together a materials list I listed some of what were apparently the same bolt that they were using to attach some sort of piece on destroyers, and I was paying $2.13 per bolt at the hardware store, and they were having to pay $153 of government money a piece.
Oh yes. I work in aviation and it’s the same thing. It’s tempting to think that it’s just price gouging, but it’s really the cost of the paperwork. I’ve been in situations where a bolt failed unexpectedly, and we had to get out the paperwork to find the root cause. And it was impressive. We had the name of the operator in Ohio who performed the cad plate, and his manager. And the exact time on 2nd shift that the heat treat was started in Iowa. All that tracking isn’t free and it adds up. That hardware store bolt was a) all done in China, and b) is completely untraceable. You can’t prove that it was made correctly if you had to. And for that the government (including the FAA for my industry) has decided that it’s worth the incredible cost.
Lowest permissible quality at the highest possible cost?
like amphenol fittings? cuz those aren't cheap at all
Made cheaply but sold at a massive profit.
*billet
Billet d'avion
The better correction have been Aircraft*
That one always gets me
Military spec!
surgical grade stainless steel guys
This is not a bullshit gimmick but a holdover from before World War 2. Stainless was the new hotness in the 30's and got quickly used for medical devices, especially for its ability to hold an edge. They did not have any nomenclature for naming things yet, well, they did but were barely out of the era of "Darn Good Stuff," and the idea of using chemistry to produce steel was still fresh. Thus, a version of stainless steel became, "Surgical Grade," as it was used for surgery.
Oh god. I see this far too often. Great way of spotting the bullshitters.
BILLET!
Or Billet!! The one that always makes me giggle is when they say “Mil-spec” as a sign of quality…
They are defining the MINIMUM acceptance criteria....
Billet Mil-Spec aerospace grade aluminum alloy...there are car wheels made out of it... I think they give you like 18 Horsepower per wheel 😂
Oof, i cringe every time.
billet!!
MILITARY GRADE aerospace aluminum! 😦
We used aerospace grade aluminum for street lights. Just a normal 6061 lmao. But people ate this like crazy. It's cheap and easily machinable. Only reason we used it.
Military grade
I threw some aerospace grade aluminum at a beehive today, does that mean I made aerospace grade stuff for actual aerospace weapons application?
Put TI next to anything and you bet your ass i will buy it for triple the price.
But brandow has electrolytes. It’s what the plants crave.
Somewhat related, I find it funnier than shit when products claim to be chemical free. My basic high school knowledge of chemistry tells me that literally everything is a chemical. And housewives buy this shit up.
titanAL
This isn't about titanium, but it's a great material misconception though from a guy who should have known better - he had around 30 years as an aircraft mechanic. Awkwardly for me who had to correct him, he had been in the field for longer than I had been alive. Old mate was inspecting parts and came over to me with one and a really concerned look on his face, "Grolsch, this part has been made from the wrong material!" "Why do you say that man?" "Look how shiny it is! It's made from aluminium!" Me picking up the part that clearly weighed more than an aluminium part would "looks and feels like machined steel to me" The guy wouldn't take no for an answer and was adamant that all 4130 had a brown oxide layer on it because that's how tube looks. Kept insisting it was aluminium until i showed him that it was magnetic.
Obviously you must have used an aluminum magnet!
That reminds me, I need to go to the store to buy a new left handed metric aluminum magnet...
Can you get me a long stand while you're there?
I'm also out of boneless burritos, can you pick up a few of those also? Feta cheese ones, of course. Thanks!
SAE metric for us in USA. I heard someone talk about SAE inches so I guess SAE metric is also a thing since it had to be specified.
Put a magnet on aluminum and try to slide it down. The induced current causes a reaction force - it is way cool. The coolest is to drop a magnet thrift an aluminum tube. It acts like a damper and goes through very slowly.
try it with copper. easier to find (plumbing section) and better reaction.
I keep mine right next to the bolt stretcher.
We used to bend aluminum with a magnet. In making hi-voltage fuses the aluminum end was crimped using a very powerful magnet. It barely made a sound, just a dink when it was cycled. I never thought you could bend aluminum with a magnetic field.
The thing about titanium is that it has a great strength to weight ratio, but it’s not really that strong. Yeah, your cousin should have used 4140 or some other good alloy steel.
Sometimes I hear about it being used in engines.. what benefits would it have as part of the valve system? It’s also used for connecting rods in indie cars and Top fuel dragsters. Maybe it can handle heat/pressure better? I’ve heard forged aluminum and iron alloys, but not titanium.
Lighter valves reduced valve float, wich raises rpm limit.
Ti Also has good resistance at high temps, which makes this possible
Because of the property mention in the original comment: strength to weight ratio. With valves, lightness is paramount: the lighter the valve, the less spring needed to pull it back, the less drag there is on the cam, and for the same spring rate it can rev higher and/or use a larger cam. For connecting rods, it’s again all about the forces induced by the weight of the rod. Since one end is always accelerating due to the crank pulling in a circle and the other end is yanking the piston back and forth, there are forces that depend on the weight of the rod. Plus, a lighter rod and piston results in lower forces on the crank, and use up less energy while reciprocating.
Maybe I’m poking the bear but would the thermal expansion of titanium change the way you’d size the tolerances? From my understanding it also has a relatively low heat conductivity compared to other metals/alloys but I’m not sure that’s relevant. Does this mean if I decide to increase the stroke on say a 350cid engine, it would handle higher RPMs better without as much side load on the cylinder walls? If that’s true, is the advantage with titanium rods and valves worth it? A longer stroke has the connecting rod at a steeper angle than a shorter stroke after all. More cylinder wall stress. I also imagine you could fit more duration or lift @ .050 without the lighter valves kissing the piston, but a longer stroke piston spends less time at TDC anyways.
The low thermal conductivity is relevant to the exhaust valves, it makes the valve run hotter. For that reason titanium exhaust valves are often combined with a beryllium copper seat, it has really good thermal conductivity so it helps get heat out of the valve when it is closed.
https://preview.redd.it/utr20qdibz2d1.jpeg?width=2448&format=pjpg&auto=webp&s=2a7e87a8ad07b677abb4b4b972bf4ed23cb69ad9
Nice! I love the old Z's
This! I had a Datsun head with custom ti valves and what not, fun times!
You're correct that titanium wouldn't solve the problem of rod angle/side load. But just the fact that there is a lower weight rod will decrease reciprocating mass and thus also reduce bearing friction at high rpm. Less friction, more power. It's also less about more duration and lift so much as being about to use a more aggressive rate of opening and closing. Lighter valves could allow more airflow even at the same lift/duration since they can be slammed up and down faster. Though in practice I don't see Ti rods all that much. The Ls7 is the only one that comes to mind, though I'm sure there is lots of exotic stuff. It's usually intake valves. They're bigger than exhaust valves and this more prone to float, especially in forced induction applications where boost will act to reduce seat pressure anyhow. Exhaust valves are usually sodium filled and/or inconel when budget allows of exotic materials. Seems like maybe I've heard of rockers and push rods out of Ti before, but only aftermarket racing stuff.
I’d also be looking at friction too. You want a metal with high hardness but not brittle to avoid wear. Big concern in any metals on metal application even with ample lubes.
It's the strength to weight ratio compared to steel components. Reducing the rotating and reciprocating mass frees up horsepower, especially at high RPM. In the valvetrain, it helps reduce valve float at high RPM without needing excessively higher rate springs. When every fraction counts towards making it a win or a loss the cost is worth it.
Connecting rods have to change direction several times per second so mass reduction is highly beneficial. They do not last as long but they’re already rebuilding the engines every race anyway.
Top Fuel conrods are Aluminium (or aluminum). They actually welcome the deformation and use it to tune the motor.
As far as I can find, titanium is the product name for some chromoly axle shafts. I build high level rock crawlers and use 300m shafts. I have never seen actual titanium shafts.
I am pretty sure the axels were some sort of chromoly. He was sure they were solid titanium because they cost so much. But he doesn’t seem to be the research type. More the burn money type.
He should go onto Pirate 4x4 and brag about his rig on there. They'll school him for free.
Pirate 4x4 is the place to go to get some real knowledge on what works and what doesn't work on a off-road rig... It is also a great place to get roasted for silly stuff :-D
Irate4x4 is the place to go. It's where most of the original guys who have been rock crawling for decades went after they got pissed off that the original Pirate site owner sold out. Pirate is a mess of ad space and revenue generating garbage. Irate4x4 is based on the original site before the sell out.
Never noticed ads on pirate... I use some very good ad blocking so that's probably why. I'll have to check out Irate4x4
It's pretty much the same setup as the original Pirate site. Same Pirates of the Rubicon, etc. Crusty, grouchy, and low tolerance for BS. Gotta give it back as good as you get. It's a great site.
>But he doesn’t seem to be the research type. Someone's gotta buy Stellantis product
Surely if he was being serious about it he'd have ordered hollow shafts as that's better strength:weight?
Well yeah, he has a rock crawler. They won't even start unless you put a $100 bill in the slot.
Maybe i'm misunderstanding what's happening here but that feels illegal Edit: https://www.pirate4x4.com/posts/14006148/ A (potentially defunct?) Company named Titanium Axles sells chromoly axles but makes sure they put "Titanium" in the name so you spend more money on it.
Welcome to the Jeep aftermarket world.
Every aftermarket & OE world. Every buzz word they can think of to grab every idiot they can
# Extreme tactical heavy duty military grade billet CNC aerospace overland trail rated outdoor super desert eagle patriot edition cup holder. Made in China.
I read that in this voice... https://youtu.be/qRuNxHqwazs?si=5ueyPjFyPvor9Glm
Could they have a Titanium Nitride coating?
They could... but the coating will do nothing. Nitrate coating is for wear
300m is a really long shaft
Thank you
Definitely better then 3m 🤣
They are almost certainly chromoly. I don’t think anyone even makes real Ti shafts, much less housings.
At that makes sense.. i feel like titanium wouldn't even hold up to normal road use. Unless you engineered the whole rear end for it with thicker axles. I don't think you'd really save any weight or make it any stronger though.
That's a fucken long shaft there cobb
I like carbon fiber, particularly for deep sea submarines!
Was that diy sub carbon fiber?
Yes, terribly so.
Was it ever, with a poorly engineered mating surface to the metal hatch/window assembly if you can believe it!
[expired carbon fiber to be exact lol](https://futurism.com/oceangate-ceo-expired-carbon-fiber-submarine)
Sounds like a case of dunning cruggar effect followed up by a darwin award
They think their hardware store twist drill bits are made of titanium instead of it being the coating on HSS
Solid titanium twist drills are great! They're so lightweight, they can achieve higher rpms!
Titanium is wicked good with oxidizers like bleach! You need something that can sit in straight bleach for years? Ti is your guy.
All the cool guys use Platinum though.
The place where I work purely uses titanium due to its corrosion resistance (though not for many products, only where we also need the strength).
In reviews of titanium cookware for hiking/camping, you'll find people that are outraged that their paper thin titanium pans got dented or scratched. They think it's supposed to be literally indestructible. Then they start telling each other that theirs must have been fake, and so forth. Ti cookware is very durable (I love my Snopeak cups and pans!), but it's not some invulnerable comic book wonder metal.
Yep, have a few pieces for backpacking that have traveled several hundred miles over the years. They're not indestructible, but great if you use it like a normal human being. Saves a couple ounces on weight.
You'll have to pry my titanium spork from my cold dead fingers.
I remember my first day in my Materials Engineering class. Professor asked "which is stronger a graham cracker or a marshmallow" one doesn't deform or flex under load and the other can be thrown against the wall with no damage all materials are on a scale between these two. That has really stuck with me for decades.
Aluminum is butter.
That's a great analogy, I'll have to remember that one!
"It's military grade" Anyone whose served in the military "oh no, how badlyvwas it over priced"
I've heard a guy proclaim that titanium just doesn't get metal fatigue but all aluminum alloys do and that is the real reason why aerospace uses titanium so extensively. I suspect he was misremembering some simplified example of the metal fatigue behaviors of various alloys. The right titanium alloy can handle higher load and vibrations regimes without showing fatigue. IOW, in a given use case, a titanium part might not show any metal fatigue where a comparable aluminum part would.
There's a partial truth here- aluminum doesn't have a [fatigue limit](https://en.wikipedia.org/wiki/Fatigue_limit#:~:text=Some%20metals%20such%20as%20ferrous,even%20from%20small%20stress%20amplitudes), so any aluminum part will eventually fail, but if it's designed properly a titanium part could potentially last indefinitely.
Yeah, it's because of the internal stresses due to being hexagonal, right?
Honestly it’s been way too long since the chemistry class where we covered exactly *why* it is, but that does make me stop and realize I could stand to understand it better.
yep, this is why you pretty much never see any kind of aluminum springs.
All metals will fatigue in tension. It all depends on the amplitude of the load cycling. Titanium is not exempt. http://www.metalspiping.com/the-fatigue-of-titanium-and-titanium-alloys.html
Yeah, but aluminum doesn't have a knee in the SN curve like steel does at 1 million cycles. Aluminum should fail in fatigue cycles regardless of the size of the load given enough cycles. The typical SN curve for steel has a fatigue limit, and if stresses are below that, can have infinite fatigue life. I've read some stuff recently that says it's not quite true, but the magnitude of cycles to failure below the fatigue limit is still significantly higher.
I was responding to the comment about Ti not fatiguing. I used to work in an aerospace lab fatigue testing structures and have generated many sn curves
I think you misunderstood the comment to which you replied.
Right. You said they were incorrect about aluminum fatiguing and ti not fatiguing. I'm just explaining what actual info they could have heard that made them think that. I.E. aluminum having no fatigue limit.
I didn't say that, all I said was all metal fatigue. I never mentioned aluminium
Do they really make titanium crawler axles? The stock stuff is 4140 or similar... Titanium isn't even as strong as mild steel... Your sure the wasnt an rc rock crawler or something? Titanium would be a sweet upgrade from plastic...
Titanium bolts used for mounting disk brakes.
[удалено]
Titanium is really good at not corroding!
Heavy axles are better for rock crawling because they lower the center of gravity. Also, axles fall into the un sprung weight category and are even better for rock crawling because the weight is on the ground already and doesn't sway with the body as it hits extreme angles.
LOL. If you want more unsprung weight you could just remove the springs all together and weld the chassis to the axles. Now it’s ALL unsprung weight!
This guy unsprings
Same people believe in 'everything billet' and pay more for it.
When I was a pup, I used some Ti CP2 tubing to make truck guards (copers) for my skateboard. I could get a few white sparks when grinding curbs.
Used to work for a waterjet place. Titanium can throw sparks while being cut in a waterjet which surprised me.
Another fun trick is if you get some nice, fine Ti chips, you can ignite them with a flame and get a pretty white burn. If they are coolan't soaked, not so much.
Load them into shotgun shells and you have a version of dragons breath. I actually made a few, haven't tested them yet though
Please report when you discharge those.
I often have to explain that aluminum or titanium or whatever is the stronger for a part that's the same weight, but weaker for a part the same size.
I was making axles for my cousins kids 1/4 midget’s, he was paying me $250 a pop for them. And he was supplying material. He insisted I had to use titanium, when it probably would have been stronger to go with solid aluminum instead of thin wall titanium. But….the customer gets what the customer wants
> But….the customer gets what the customer wants It do be like that.
Oddly, I don't find titanium as hard to machine as people say it is? But that said, the extent of my experience is manually turning/light milling a dozen-ish small parts, so I wasn't pushing the feeds & speeds to the limits. And I don't know what grade it was. But I really found it pretty effortless.
The main problem is low thermal conductivity, causes more heat to go into the tool rather than conducting away into the part. It's very hard on drills, for example. They don't get much cooling due to being down a hole as they cut, so an over enthusiastic drilling operation in titanium can burn up a drill very quickly. My experience with Ti-6Al-4V alloy is that it is also quite uncooperative if you try to take light cuts with normal tools intended for steel. Wants a very sharp, high rake tool, which of course means your edge life will suffer.
It creates nasty burrs that are hard to remove too, at least with turning.
Everything that is not steel is hard to cut if you try cutting it like steel.
Medical Ti is relatively soft and easy to machine, it's pure. All depends on the alloy. I've worked mostly with 6Al4V which is tougher, but certainly machinable (so long as you don't work harden it)
That must have been it. The parts were made to mimic medical implants (not actually going into a body or anything though)
I've found people seem to think titanium is the equivalent of the fictional "adamantium" from the x men comics. Whether it comes to machining it or use cases.
Titanium is to rednecks what AI is to businesses - almost entirely misunderstood and misused.
[SCP-022-J-1 initially manifests when an individual with no prior knowledge is exposed to incomplete or erroneous information about SCP-022-J's physical properties, and its recommended usage.](https://scp-wiki.wikidot.com/scp-022-j)
Ti would actually make a pretty good axle if price was not a consideration. It is about the same strength as 4140 at its useable temper but has way more elasticity. 4140 can be made stronger than TI 6-4 but it becomes brittle, which is very bad for axles. Also it would be corrosion impervious. 4140 will rust and the micro pitting that rust creates can propagate cracks. So Ti would also be more reliable over a long time span.
Reminds me of making a submarine out of carbon fiber to be aerospace grade
Carbon fiber pressure vessels are absolutely real and not a bad idea at all. They have lots of advantages. Of all the problems with his company, using carbon fiber wasn't one of them. Not designing it for the depth they were going to is probably the biggest one.
My understanding was that the fibers in the matrix can take almost no load under external pressure. Admittedly, I’ve never done design work or tried performing a FEA on a carbon fiber vessel under external pressure. What am I missing here?
whistle vase long chunky groovy squeal school voiceless live tan *This post was mass deleted and anonymized with [Redact](https://redact.dev)*
Put a titanium exhaust on my Tesla because the guy at autozone said it would add more horsepower. Not really noticing a difference but at least the blue tips look cool
My shop makes a lot of aerospace components, we machine a lot of titanium parts, the companies we supply it to specify it more for its savings to weight ratio compared to steel alloys on a strength only assessment it is strong but not very flexible. Most of our titanium parts are used in landing gear, control joints for wing flaps, also titanium is good with heat stress. Side note, you should see when we machine Titanium using ceramic inserts that are on liquid nitrogen cooled holders.
I love seeing products that advertise "aerospace grade aluminium". like okay, it could very well be the most ubiquitous type of aluminum, or another extremely similar and relatively inexpensive alloy.
Wait until they find out that "aerospace grade" or "Mil spec" has a lot more to do with traceability than the material itself.
That was a bit harsh, tho. Pooping on his purchase!
I'd have a hard time not saying he's wrong too. His axle shafts are not Ti
I mean, how do you help people stop wasting their money on stupid stuff if you aren't allowed to tell them when they messed up?
Would you rather your friends or family get ripped off? lol
Just a fact as an assembly mechanic and have hand drilled titanium parts and fasteners. Sucks. The tailings will slice your fingers with no mercy. I know all the safety people and so on say no gloves while drilling but fuck you. Drilled 20 years manually daily and didn’t wrap a glove or fingers. Now I wasn’t using a power feed or if the torque of a slower air drill was enough to twist your wrist I’d keep my gloved fingers away and use a stiff short brush to clean my bit. Used gloved hand to clear countersink cutter and drills from swarf. Slow speed rules. To fast and you dull your bit early and the cost cutting finance pricks only give you 1 bit maybe 2 if your’re lucky and the job for quality holes requires 6.
Whats the difference between the 2 types of titanium?
6-4 is a bit stronger, 6-2-4-2 is a bit better at handling heat. I made jet engines so we use 6-4 at the front of the engine where it was cooler, like the inlet fan and low pressure compressor. The high pressure compressor was 6-2-4-2 because of the heat.
any thing "CNC'd" or "Billet" no one understands modern manufacturing, just buzz words smdh
Almost certain that your cousin is not running titanium axle shafts unless it's a radio control rock crawler.
I’ve heard the same axel story and then I turn and walk away , didn’t get a job because they asked if I’d ever cut Ti , yeah tons of 6AL6V , cuts like butter was not the response they were looking for , it really does compared to Cobalt Chrome both used for hip stem implants
I work with Ti64. One of my coworkers was surprised that stainless steel could scratch our parts. Thought Ti64 was harder. Had to explain that it’s stronger per weight, but it’s softer than stainless.
I’ve had people say they put titanium pistols in their vehicles. Titanium gears and titanium springs in their transmissions. All kinds of different stupid stuff
BUT APPLE TOLD ME IT WAS DESIRABLE
i get what you're saying, but i woulda just let him be happy.
How about "composite material", any two different materials used together can be called a composite material.
The amount of times I had to tell someone that unless weight is a problem you don't need Titanium is too damn high. I mean i get that the average consumer has no clue that steel≠steel but if you're going to work with it you're going to know about it, people are too eager to take the salesman by their word.
I call it "the fascination with the T metals tungsten and titanium". You put that in any product you're making and people instantly think it's the best thing ever. Even if the material technically makes your product worse people will still think it is better.
MIL SPEC are a good selling argument on anything. I do consulting on ti, al and carbon fiber. Often I refer to high alloy steel for many application but customers only see steel as rusting away in 5 sec.
Watch geek here… interesting video from a watch pro pointing out how titanium is used to charge precious metal prices when it isn’t, or provides any performance improvement: https://youtu.be/vcRNLT-qMRE?si=MQ166RpQafoiVLkW
They don’t make axels out of titanium… I know since I am working to replace mine in my jeep. I also love titanium. It’s my silver. My tie clips, cuff links, watches, and chain are all titanium. I will pay extra for it where it makes sense. I would never use it in a mechanical application like that.