[Phil P]

quote:Originally posted by Overlord

Yes, 400 series SS is heat-treatable with some of it's alloys coming close to carbon steel tensile strength, but is not as rust resistant as 300 series(which can't be hardened with heat treat).

The lug nuts that were linked to earlier in this thread by jsmitfl. being sold on ebay, are described as 100% 304SS. These are the ones that I was referring to as being dangerous. I notice that now, when I clicked the link, they are no longer there, .....coincidence?

100% 304SS is not strong enough for lug nuts! ...period!

...and, yes, if you grease or use anti-seize on your lug nuts, reduced torque values are very crucial to not stretching the threads and causing failure.

Hi

Very good post I just didn’t look up the alloy numbers.

I received training from one of the largest fleet owners in the US. They had a video of the “clamp” pressures obtained by using lubricant on the threads and using the “wet” torque value. They had a setup with a strain gage to show the deference. They were using the ½ 20 lug nut to demonstrate this.

The clamping pressure obtained by using lubricant and the 105 Ft Lbs torque was more than double that of the "dry" thread torque.

They did stress that the lubricant “high temp anti size” should not be put on the tapered face of the lug nut just the treads and not in a quantity that would allow the lubricate to squeeze out onto the tapered face of the nut and wheel.


Phil P