Anybody have any experience? Are they strong enough to torque to 96ft-lb? Its a M12x1.75 hex head.
They rate it at around a tensile strength of 120k psi.....same as a SAE grade 8. I misplaced a bolt for my BBK after taking it to advance to size the allen head on it and bought this as a replacement. What worries me is that it was CHEAP! Ive paid way more for some SS bolts for my exhaust. These are a lot more important then an exhaust bolt.
Does the torque rating for a hex head differ for a rounded head that is driven by an allen wrench?
it should be fine.
i believe most lugnuts are grade 10.9
The main problem I had with the Advance bolt I used on my suspension: the damn thing rusted really bad in only a matter of weeks. Was a PITA to remove.
As far as the strength goes, it's probably fine for the short-term.
dave99rt Wrote:it should be fine.
i believe most lugnuts are grade 10.9
you mean the actual lugs? Those are pretty strong bolts that withstand multiple torquings of 80-90ft-lb.
The bolt I bought was black, guessing its a anti rust coating? Should i spray them with paint after i torque them?
My charts listing all of this stuff are at work, so going to have to do it the long way.
Tension in a torqued screw is approximated by T=(K)(Fi)(d). K being the coefiicient of friction estimated at .2, Fi being bolt force and d being minimum diameter.
This equation give Fi ~ 12,000 lbs when T=96 ft lbs
Then find the area over which this load is carried, in this case A~=.17 square in.
Then find the stress in the screw by sigma=F/A
Doing so yields a screw stress of ~= 71ksi.
I would estimated that the Proof Strength of that M12 screw is ~= 75% of yield or 90ksi.
You are good to go.
Edit: Also, hex head versus socket head cap screw. Although the ratings are the same, socket heads are considered a more reliable screw as the stress is more evenly distributed on the cap itself.
Awesome stuff in the above post joe! I got excited and nervous when I saw you had posted cause you would either give me the good news or the bad news. Thanks for the help.
Going to test the bolt today!
They should be fine! I have never had problem with advance bolts. If it makes you feel more comfortable. Go to ACE hardware and buy them. I think they are all hitman or something like that. But they are very good quality hardware.