This method is more accurate for torquing nuts and bolts, as it eliminates the variations and uncertainties of torque wrench readings due to friction. The tension developed within the bolt or stud by using torque applied by a specific rotation of a nut or bold for so many degrees is not altered by friction.
The developed tension load in stud or bolt = [cross section area of the stud or bolt]x[modulus of elasticity of the stud or bolt material]x[delta (change in length of the stud or bolt by the applied load due to the specific degrees of rotation of the bolt or nut)] all divided by [length of the stud or bolt].
or: P = AE(delta L)/L
You can see that there is no way for friction of the threads to enter into the developed tension in the stud or bolt, thus torquing this way (to develop a specific tension in the stud or bolt) is much more desirable.
89 Milano (wife's daily driver since 1989)
91 164S (my daily driver since 1994)
94 164LS (~Q) (trip Alfa since 2000)
72 Morgan 27 (water time since 1976)
previously owned since 1964:
62 Morris MiniMinor 850, 67 Austin 1275 Cooper S (Downton 3/4 race), 64 Giulia Sprint GT (1st red one made), 72 Fiat 128 Sedan, 75 Alfetta Sedan, 78 Alfetta Sedan, 78 GTV, 81 GTV6, 86 GTV6
Last edited by Del; 04-14-2009 at 04:28 PM.