Spool Splines

[Chris Hill]

Originally Posted by Myron Piatek

I have always heard that maximum strength is achieved when spline engagement is at a depth at least the diameter of the axle shaft.

I think the same theory (and rule) applies to wheel studs and their engagement into the main body of the lugs.

The design rule of thumb from my engineering class is engagment needs to be 1 1/2 times diameter. I think this is for grade 5 fasteners. Though we all know this can be less if in a pinch.