Final answer:
Bolt grip lengths should be one and one half times the thickness of the material which is fastened together, according to newer work.
Step-by-step explanation:
The correct answer is C - one and one half times the thickness of the material which is fastened together.
According to newer work, bolt grip lengths should be as much as 8 diameters side-to-side and 15 diameters deep. This means that the grip length should be one and one half times the thickness of the material.
For example, if the thickness of the material is 2 inches, the bolt grip length should be 3 inches (2 inches multiplied by 1.5). Generally speaking, bolt grip lengths should be equal to the thickness of the material which is fastened together, plus approximately one diameter. This guideline ensures that there is sufficient engagement between the bolt threads and the nut or tapped hole. The additional length provides for secure fastening and allows for some protrusion past the nut, which can be important for inspections, to ensure proper thread engagement, and to allow for material expansion or contraction.