ABSTRACT
In the last chapter we studied the strengths of the materials from which threaded fasteners are
made. Now we will look at the resulting strengths of those fasteners themselves. As we do this
we should remember that the bolt’s job is to clamp the joint together firmly enough to prevent
slip, separation, or leakage, and that the bolt must be strong enough to support the maximum
preload it receives at assembly, plus the maximum additional loads it sees in service as a result
of forces applied to the joint, differential thermal expansion, etc. When designing, evaluating,
specifying, or selecting a bolt for a particular job, therefore, one of our first questions will be:
‘‘Is this bolt strong enough to clamp this particular joint?’’ As we’re about to see, the question
is much simpler than the answer, because there are many aspects to the concept of strength
when we’re dealing with a bolt.
