Technical Info

At Birmingham Fastener, we aim to provide you with the knowledge and tools for your project. Our constantly expanding Fastener Learning Hub is full of information and insights for a variety of industries. View bolt length charts, read product comparisons, and find answers to your questions about fasteners.

Diameter of Bolt	Bearing Surface Diameter	Bolt Head Height (max)	Bolt Head Height (min)	Length of Spline	Diameter of Spline Reference
5/8	1.102	0.403	0.378	0.6	0.43
3/4	1.338	0.483	0.455	0.65	0.53
7/8	1.535	0.563	0.531	0.72	0.61
1	1.771	0.627	0.591	0.8	0.7
1 1/8	1.991	0.718	0.658	0.9	0.8