Understanding Bolt Torque vs Clamping Force

[Bob Bidonde]

When the Model "A" was produced, there were no torque wrenches in use at the factory. The first car company to use torque wrenches was Chrysler in the mid 1930s. The torque wrench became available on the retail market in 1938. Being an engineer and knowing the pains taking design of structural joints, it is questionable when torque tables are arbitrarily applied to the Model "A."

We all know that tightening a bolt causes a clamping force, but how much is the clamping force? The attached table provides the amount of clamping force. So when you see a book that says torque to XXX Lbs-Ft, understand how much force is being applied, and does it pass your "giggle test."