Torque and Chrome

Torque on Bolts?

Why does the torque settings differ on a variety of components when there is a standard list published. On that list , it is explained that these torque settings are onle to be used when the manufacturers specs are unavailable. How do manufacturers then go about calculating the ideal torque? The torque wrench is in any case inaccurate due to friction and a list of other factors. There are far more accurate and expensive items to measure, but for a motor repair shop, how does the the engineering shop calculate the cylinder head torque on vehicles and why does it differ? Just so that we are clear, im talking about comparisons between two identical materials?

Public Comments

1. Bolts and nuts are subject to differential thermal expansion due variation of material grade. Also bolts are subject to different operating stress conditions and temperature depending on application. Manufacturer's of equipment are in a better position to asses it . Standard charts are thus for guidance only .