Does Ti actually make for a good lug nut, or do they become a wear item like aluminum lugs?

 

They've gotta be more durable than AL but not sure by how much or how it's related to steel.

I almost pulled the trigger on these in the past but was hesitant for the same reason and, well didnt really want to spend the money. But in fairness they arent that expensive for Ti lugs.

https://ozmoengineering.com/shop/m12...nical-lugnuts/

 

When I finally get a real shop space the next machine I order will be a lathe with live tooling. I've thought about filling my open time with just Ti hardware for common large steel things. Wouldn't make much money but I could Ti my whole dang car while keeping the machine busy.

 

Is that the way to do it? I thought I read somewhere that cut threads are inferior to rolled threads. Any merit to that or marketing doing their thing to differentiate from others?

 

Absolutely correct. But you can roll threads on a CNC lathe with the right tools. Internal threads can be done with thread forming taps. It'll be super scary getting that recipe dialed in Im sure

 

Could it be reasonably outsourced for now after you design em?

 

Nope, the margin in profit is so small on Ti hardware that unless you're making it I don't see a compelling reason to source it. Unless it was thru China/Taiwan which I wont do cause of material variability.

Its just something I thought about doing when I have a lathe to have it continue to add value and not sit waiting for projects. Working on that plan for full timing my business.

 

For the record, Ti does work fine as a lug nut (cost aside). Aluminum doesn't have an endurance limit so it will always permanently stretch every time you torque it. Steel and titanium both have endurance limits so when they're torqued they stretch a bit but when they're untorqued they spring back to their original length. That's the entire reason why Al connecting rods have to be checked on a regular basis for stretch.

 

I run alum lugnuts, have been on the same set for probably 100+ torques to 85 ft-lbs. Alum may not have an infinite fatigue life but we also arent cycling load on these in a fatigue life scenario where we can say it will last x cycles.

Its still in the low cycle range where its either going to hold or not hold. If you torque to yeild, yeah itll fail. That takes just 1 cycle not 10s of cycles. People seem to have a total misconception of fatigue life and the cycle volume it takes before its a critical component.

My steering arms are designed around stress loads for 7 figure cycles at peak load. Think about how much driving it would take to maximum load them to a 7 figure cycle range? Its longer than your car would last. IIRC, 7fig fatigue life is in the 100mpa range compared to the yield strength of 270mpa.

Now look at 3figure fatigue life on aluminum, oh wait, you cant. Its too close to the noise that you basically stick to proof strength (80% of yield strength) and it will last as long as you dont damage them. How much torque is that? Well you're going to have to look at total thread engagement to calculate that one. On an M12x1.5 stud, with 15+mm engagement that torque is 80-110 ft-lbs on a 7075 nut.

The only thing to be more cautious about with alum nuts is thread angagement. Around 8 turns (12mm) is the min Id run on steel and 12 turns (18mm) with Alum. I also keep a spare set of steel lugs just in case

 

I have aluminum lugs nuts that I stopped using because I am scared.

 

Every car I've worked on with aluminum lugs nut, at least one on every wheel is usually ****ed up ****ed up. The weight penalty of steel for such a small item isn't big deal to me. Also they usually look like **** after getting gunned off a few times.

 

Do I need to post pics of my nuts? lol. I rotate or swap tires probably 30-40times per year, maybe more. Always gunned off on high torque and zipped on at low torque, then torqued with a wrench to 85 ft-lbs.

They are also now at least 4 years old. Trying to find exactly when I bought, but it was the same year I pulled the AC which was not recent . So yes, literally hundreds of fully torqued cycles.

Treat them right, keep a back up, check often. There is no problem.

Edit: I also see peaks over 1.6g on concrete and 1.5 sustained.

 

Possibly the amount of times you take them on and off saves them. VS remaining installed for months at a time and corroding with the steel stud.

 

I'm not questioning a control arm made of Al as that's a whole different scenario and I agree with what you've said. But on lugs there's also heat that can weaken them coming through the hub.

In an autox setting I'd be far less worried about using them vs track setting. I'm willing to take the extra 1-2lb penalty for not losing a wheel at 120mph. I've seen enough guys lose wheels to Al lugs that even if I do all the calcs and they say it's fine I'm still not going to do it.

 

Not all alum nuts are made the same, but, The obvious hardness difference of an ARP stud Vs the brittle threads on an alum nut are what steered me away. I launched 2 or 3 of the BC ones in one weekend threading by hand and put open steel ones on that same weekend. Like mentioned the unlike materials are half of the issue unless you get Dallas's unobtainium ones