Wheel Torque

[EricNMN at aol.com]

Richard,

When an ME (we're good guys - really) specifies torque, the sizes and materials of the bolt/nut/stud are (should be) known.  The bolt size and material strength determine the amount of tension the bolt can handle.  The friction between the bolt and nut is (should be) considered.  Yes, the bolt with anti-seize is tighter, and the connection is stronger (assuming you have not stressed the bolt beyond its limits).   But, if you overstress the bolt, it will change shape (lenghten or distort the threads).  That could mean it won't fit easily into the nut.  A bigger negative (albeit unlikely) is damaging the threads on the hub.  If this happens, a new bolt would be difficult or impossible to install.  You'd then need to replace the hub (more costly).

Please refer to my posting earlier today for some tech details.

I'm sticking with a wire brush to clean the bolts, replacing them if they look damaged, using the factory torque settings and no anti-seize.  I live in Georgia and don't encounter a lot of the salt spray, etc that folks up north receive.

Eric Schumacher

Date: Tue, 22 Oct 2002 08:14:53 -0700 (PDT)
From: Richard J Lebens <rick-l at rocketmail.com>
Subject: Re: Wheel Torque

Help an EE get a handle on this.

When they (MEs) specify a torque on a bolt, which should set the tension along the axis of the bolt do they also add in the coefficient of friction between the steel to steel junction of the threads?  The rotary motion being converted to linear motion by sliding two inclined planes together? Is this why adding an anti seize (lubricant) will mess this up?  Is this why you're supposed to torque the bolt in one continuous motion?

Wouldn't anti seize make the bolt tighter?