Does the length measurement of a bolt include the head? In most cases, when specifying the length of a headed bolt, the thickness of the bolt head is not included. For instance, if you were to order a ¾” x 24” hex head bolt, the bolt would measure 24” from under the head.

How do you measure bolt length?

Measuring Bolts and Screws

Length is measured from the point at which the head sits flat with the surface, to the tip of the threads. Hex, pan, truss, button, socket cap, and round head screws are measured from right under the head to the end of the threads.

Are bolts measured by head or shaft?

Head Diameter

It is common for people to refer to hex bolts by the size of the head measured across the flats (this is also the size wrench the bolt uses). This is incorrect and should be avoided for two reasons. Miscommunication can result in getting a much larger bolt than needed.