[Got f1?]

Have an opportunity to get some titanium studs at a great price. Several people have mentioned galvanic corrosion and general brittleness (my word not theirs) makes them not ideal.

Anyone have first hand experience with titanium studs? How has the longevity been? Any issues?

[to_riffic]

Have Racenseng Ti studs. I used to run MRG studs but they're more susceptible to galling than the Racensengs Ti studs. The downside is that they definitely have a slight difference with their threading as regular nuts. I tried putting MRG nuts on there to try and do reverse locking 2 nuts to take off the studs, and it wouldn't go on. I haven't tried regular nuts yet, but this was back when I was getting the brake ducts put on and ended up dropping it off to my local shop to do it instead.

Anyway, I really like them, but they're insanely expensive. I think it was like $1k new, and that was like with 20% off military discount.

Also, I don't think I needa hear the whole Ti vs steel debate. I've ready it and seen the videos etc etc. I'm playing with fire using them at the track, but that's why I have track insurance and take my time taking wheels on and off since I swap them regularly. Plus, I just love the lack of corrosion on them...

[swcc50]

Which kit are you getting?

[Got f1?]

Originally Posted by swcc50

Which kit are you getting?

Not sure. A friend that owns a suspension shop has them. He races so presuming the quality is solid. Just hear so much issues about being brittle and with corrosion from other metals.

[Hapkin]

Any idea on weight differences? Interested if it will make a difference in driving response.

[Track/S]

Originally Posted by Hapkin

Any idea on weight differences? Interested if it will make a difference in driving response.

-50% +-

[aroundelway]

45% actually but it’s a dumb place to spend money. If you could guarantee the ti is from a reputable source I’d say why not, it’s your money do what you want.

However, the world is now full of shitty Chinese or Russian ti sourced through China of dangerously low quality because it is reclaimed metal from god only knows where with who knows what mixed in.

Years ago we had to throw away a batch of ti the Russians sold us from a cut up submarine but that’s another story.

[Track/S]

Originally Posted by aroundelway

However, the world is now full of shitty Chinese or Russian ti sourced through China of dangerously low quality because it is reclaimed metal from god only knows where with who knows what mixed in.

Years ago we had to throw away a batch of ti the Russians sold us from a cut up submarine but that’s another story.

That statement is a bit doubtful, knowing that Boeing the ti that it uses is Russian.

Did you buy titanium from a submarine to later use it in aviation? Or did you want supreme quality at a bitch price? Interesting story...

[///MPhatic]

I had these on my Lotus for a while because I got them at a great price. I liked the 2-piece design, but that's where it ends. Too many issues with Ti lugs, so I went back to standard.

[Got f1?]

Originally Posted by ///MPhatic

I had these on my Lotus for a while because I got them at a great price. I liked the 2-piece design, but that's where it ends. Too many issues with Ti lugs, so I went back to standard.

What issues did you have?

[///MPhatic]

Originally Posted by Got f1?

What issues did you have?

Even after a short while they didn't want to come off. Apparently I keep my cars too clean, and the dissimilar metals don't play well together. I also had a few loosen themselves under torque spec within just a few hundred miles. Ti is also prone to galling, but I didn't experience any of that.

I tried several before settling on the Lotus Sport lugs, and I'm quite happy with them. They're the black ones in the last pic.

[chris719]

I just don't think it's worth the risk. Weight saving is insignificant and it's also located near the center of mass.

[F87source]

Originally Posted by Track/S

That statement is a bit doubtful, knowing that Boeing the ti that it uses is Russian.

Did you buy titanium from a submarine to later use it in aviation? Or did you want supreme quality at a bitch price? Interesting story...

No, what he says is actually holds alot of weight....

1) Titanium from China, especially fasteners, are often considered to be extremely low quality because they have alot of impurities which weakens the overall strength of the titanium fastener. Manufacturing process also has poor levels of QC meaning the fastener is more susceptible to failure.

2) Lockheed martin purchased titanium ore from the soviet union to build the SR71, but the key difference is that it was titanium ORE, and that means it was refined and QC'ed in the USA. This likely is the case today with boeing, I doubt they purchase anything but the base material to be refined in the USA.

Also, aero space grade titanium is no the same as cheapo chinese grade titanium, it has significant QC requirements to go through before it makes it onto an airplane. So you cannot draw the same comparison in saying just because boeing uses russian titanium, that means all titanium from russia or china is equally as good.

[F87source]

Originally Posted by chris719

I just don't think it's worth the risk. Weight saving is insignificant and it's also located near the center of mass.

+1


Also because titanium studs will have a lower tensile strength than steel studs, and here is why: despite titanium having a significantly higher tensile strength to weight ratio vs. steel, the key thing to note is strength to WEIGHT ratio. So for 2 similar mass pieces of metal, the titanium one is going to be much much stronger, but you must realize the titanium piece will be much bigger because it is lower in density you will need more of it to reach the same weight.


So when it comes to fixed sized objects like wheel studs (where you cannot make them bigger because the hole is fixed in size), both the titanium and steel studs will be the same size. However, the steel bolts will be much heavier than the titanium bolts. So when you calculate tensile strength to weight, the steel actually will have much more tensile strength because it is significantly heavier. So for the same sized objects the steel option is stronger, this is why you see titanium bolts break on track but you don't see steel bolts break at the same rate. You also have to factor in the titanium's grade and quality, and since most wheel bolts come from China, we don't see the greatest quality and we don't see the strongest grade of titanium in use. We generally see grade 5 titanium on most bolts, because that is the most common grade of titanium.

Here's a thread about this:
https://f80.bimmerpost.com/forums/sh....php?t=1356233



Now this relation ship between tensile strength and weight doesn't always have to favor the heavier object or lower tensile strength to weight ratio object, it just so happens that the delta between titanium's tensile strength to ratio vs. steel's tensile strength ratio wasn't large enough to make up the difference. But something like carbon fiber (a specific weave and grade of course) can make up the difference and then some, because carbon fiber has a ridculous tensile strength to weight ratio, to the point where it can be significantly lighter yet stronger than a steel part.



Edit - don't believe me? Go get 2 similar sheets of metal, one being steel and one being aluminium. Try to bend both, what do you notice? That's right the aluminium one is easier to bend. Now try to use some metal shears and cut both sheets, which one is easier to cut? That's right the aluminium one.

[to_riffic]

oh no, did this thread become a carryover of the Ti vs steel conversation again?

[F87source]

Originally Posted by F87source

+1


Also because titanium studs will have a lower tensile strength than steel studs, and here is why: despite titanium having a significantly higher tensile strength to weight ratio vs. steel, the key thing to note is strength to WEIGHT ratio. So for 2 similar mass pieces of metal, the titanium one is going to be much much stronger, but you must realize the titanium piece will be much bigger because it is lower in density you will need more of it to reach the same weight.


So when it comes to fixed sized objects like wheel studs (where you cannot make them bigger because the hole is fixed in size), both the titanium and steel studs will be the same size. However, the steel bolts will be much heavier than the titanium bolts. So when you calculate tensile strength to weight, the steel actually will have much more tensile strength because it is significantly heavier. So for the same sized objects the steel option is stronger, this is why you see titanium bolts break on track but you don't see steel bolts break at the same rate. You also have to factor in the titanium's grade and quality, and since most wheel bolts come from China, we don't see the greatest quality and we don't see the strongest grade of titanium in use. We generally see grade 5 titanium on most bolts, because that is the most common grade of titanium.

Here's a thread about this:
https://f80.bimmerpost.com/forums/sh....php?t=1356233



Now this relation ship between tensile strength and weight doesn't always have to favor the heavier object or lower tensile strength to weight ratio object, it just so happens that the delta between titanium's tensile strength to ratio vs. steel's tensile strength ratio wasn't large enough to make up the difference. But something like carbon fiber (a specific weave and grade of course) can make up the difference and then some, because carbon fiber has a ridculous tensile strength to weight ratio, to the point where it can be significantly lighter yet stronger than a steel part.

Here is more data about tensile strengths:


1) 6k 5HS carbon fiber:
The source for this data is a carbon supplier:https://www.fibreglast.com/product/6...rbon_fiber_all

Tensile strength: 610 - 700 KSI (which is Kilopound per square inch) = 4,205.8 Mpa - 4,826.33 Mpa
Tensile Modulous (Young's Modulus or rigidity): 33.6 - 34.9 MSI (million pounds per square inch) = 231.66384504 Gpa - 240.62702953 Gpa

2) Grade 5 titanium (Ti6Al4V which is the most commonly used titanium in industry):
The source for this data is from AZO materials: https://www.azom.com/properties.aspx?ArticleID=1547

Tensile strength: 862 - 1,200 MPa
Tensile Modulous (Young's Modulus or rigidity): 110 - 119 GPa

3) Chromoly steel
The source for this data is from: https://material-properties.org/chro...melting-point/

Ultimate tensile strength: 700 MPa
Tensile Modulous (Young's Modulus or rigidity): 205 GPa

4) Stainless steel grade 304 (a pretty common stainless steel that is both very corrosion resistant and strong):
The source for this data is from Azo material: https://www.azom.com/properties.aspx?ArticleID=965

Tensile strength: 510 - 620 MPa
Tensile Modulous (Young's Modulus or rigidity): 190 - 203 GPa

5) 7075 Aluminium (known for being the strongest grade of aluminium and used in air craft):
The source for this data is: https://www.matweb.com/search/DataSh...bbf43f79c51b7d

Ultimate tesile strength: 572 MPa
Tensile Modulous (Young's Modulus or rigidity): 71.7 GPa


From this data you can see carbon has a ridculous ultimate tensile strength compared to titanium and chromoly steel. Carbon fiber is also significantly lighter than all of these metals, and it is also stronger so when you divide ultimate tensile strength by weight to get tensile strength to weight ratio carbon fiber will only have a better ratio than the rest of these metals.

If you look at titanium vs. something like chromoly steel its ultimate tensile strength is around half, but is it half as light? The answer is no:

Chromoly steel is about 7.73g/cc
https://www.matweb.com/search/datash...41c818b&ckck=1

Grade 5 titanium is about 4.43 g/cc
https://www.matweb.com/search/DataSh...8e5f825ae85390


And this is a very crude explanation as well, because wheel bolt's aren't chromoly steel and tensile strength is also dependent on material purity and manufactuing - something that is easier to do with steel because we are very good at working with steel vs. titanium which is less common and more tricky to refine. Steel bolts are also commonly made in the USA (which we have established generally has great QC) vs. titanium which mainly comes from Asia (which typically doesn't have the best QC).

[F87source]

Originally Posted by to_riffic

oh no, did this thread become a carryover of the Ti vs steel conversation again?

I'm just saying it probably isn't a good idea or worth it to get titanium studs.

[to_riffic]

Originally Posted by F87source

I'm just saying it probably isn't a good idea or worth it to get titanium studs.

I know. I'm fully aware of both sides of the argument. I certainly enjoy the look of the Ti studs and take the gamble whenever I hit the track. Lets just hope I don't fall victim to a failure. But I appreciate the feedback regardless.

[F87source]

Originally Posted by to_riffic

I know. I'm fully aware of both sides of the argument. I certainly enjoy the look of the Ti studs and take the gamble whenever I hit the track. Lets just hope I don't fall victim to a failure. But I appreciate the feedback regardless.

The good thing is that you have track insurance, that is a really really smart thing to have - especially with an expensive car like a bmw.

[aroundelway]

That statement is a bit doubtful, knowing that Boeing the ti that it uses is Russian.

Did you buy titanium from a submarine to later use it in aviation? Or did you want supreme quality at a bitch price? Interesting story

Everyone in aerospace uses Russian ti and has for decades. Them or Japan.

Other industries will source questionable quality ti from china.

My experience is in aerospace although not Boeing. That is a company run by the bean counters. They have not had a good engineering focus for thirty years and turn out products of questionable quality and poor design.

Buy what you like but I have no faith that these parts are sourced from reputable places so to me the marginal gain is outweighed by the risk of failure.

[///MPhatic]

Originally Posted by aroundelway

Buy what you like but I have no faith that these parts are sourced from reputable places so to me the marginal gain is outweighed by the risk of failure.

Perfectly stated.

I do trust Radium, but again, the possible issues aren't worth any of the gains (to me).

[Track/S]

Originally Posted by aroundelway

Everyone in aerospace uses Russian ti and has for decades. Them or Japan.

Other industries will source questionable quality ti from china.

My experience is in aerospace although not Boeing. That is a company run by the bean counters. They have not had a good engineering focus for thirty years and turn out products of questionable quality and poor design.

Buy what you like but I have no faith that these parts are sourced from reputable places so to me the marginal gain is outweighed by the risk of failure.

So how should we act to get grade 5 ti of the best quality? I would like to buy a bar to make 20 studs and 20 nuts.