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Discussion Starter · #1 ·
with winter finally over with i have put my new wheels and summer tires on the car. however i couldn't help but notice how crappy the stock lug nuts already look. i was browsing amazon for lug nuts and was shocked at how many options there are. i found sets of 20 for under 20$ and sets of 20 over 100$. a lot of reviews complained at how short lived the color coatings last on these so im thinking about just getting stainless steel, but they dont seem to exist for anything other than trailers... im assuming there must be a reason for this? are there any trusted brands out there?
 

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Yep, stainless (generally) has lower yield stresses and is not used for such things as lug nuts. That is why you see some made with a shell of chrome and high strength carbon steel underneath for the actual nut.
 

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Discussion Starter · #11 ·
so they arrived and they say to only torque them down to 75 ft lbs, however my manual sais to torque the lug nuts to 89 ft lbs. witch one should i fallow? or did i buy the wrong part here...

also i noticed the shop that mounted my winter tires on the stock wheels over torqued the lug nuts big time. i didnt test exactly how much but id guess over 100 ft lbs for sure. they were hard to get off but nothing broke so i figured im ok, but i just figured id throw that in here as well. could that have done permanent damage or as long as nothing broke is it ok?
 

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I’m not an engineer to be able to answer that question exactly but I can tell you with too little torque the nuts will work loose as the wheel expands and contracts from the heat of the brake. I’ve personally never seen lugnuts that list a torque value they just say follow manufacturer recommendations
 

· Not a mod... or is he? Or, is he not?
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Guns are made of everything from cheap plastic and aluminum to chromoly. Materials have specific uses. Just because a material is good enough to use as a punch such as M4 tool steel doesn’t mean it will work as a nut.

I would find out why from the company before install. If they mention anything about damage to the fastener send them back
 

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My bad; I was confusing chromium vanadium with chromium molybdenum (gun steel.) The two are similar, though. Chromium vanadium should be fine for lug nuts as for the steel itself. Unless these lug nuts are made of some cheap imitation recipe of that steel, they should be OK --- which still leaves the low torque recommendation unanswered.

As for your old lug nuts being torqued too much, we'd have to make a some assumptions about the type of steel 'they' are mad of to determine if the studs were damaged by high torque.

So if we assume they are at least a 180KSI tensile strength material and assume the yield is 60% of that we get 108KSI. M12x1.25 studs have about .17 square inches of cross section area. .17insqx108,000lbs/insq = 18360lbs. Using a clamp force calculator yields anything over 143ft-lbs torque will result in > that 18360lb yield number.

So that is approximate but if the nuts were not torqued past the 143ish you should be OK.
 
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