Technical Info

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A307 Hex Bolt Dimensions Per ASME B18.2.1-2012

Nominal Size or Basic Major Thread Diameter		Body Diameter		Width Across Flats			Width Across Corners		Head Height			Thread Length
Nominal Size or Basic Major Thread Diameter		Max	Min	Basic	Max	Min	Max	Min	Basic	Max	Min	Lengths up to 6"	Lengths > 6"
1/4	0.25	0.25	0.2405	7/16	0.438	0.428	0.505	0.488	5/32	0.163	0.15	0.75	1
5/16	0.3125	0.3125	0.3065	1/2	0.5	0.489	0.577	0.557	13/64	0.211	0.195	0.875	1.125
3/8	0.375	0.375	0.369	9/16	0.562	0.551	0.65	0.628	15/64	0.243	0.226	1	1.25
7/16	0.4375	0.4375	0.4305	5/8	0.625	0.612	0.722	0.698	9/32	0.291	0.272	1.125	1.375
1/2	0.5	0.5	0.493	3/4	0.75	0.736	0.866	0.84	5/16	0.323	0.302	1.25	1.5
9/16	0.5625	0.5625	0.5545	13/16	0.812	0.798	0.938	0.91	23/64	0.371	0.348	1.375	1.625
5/8	0.625	0.625	0.617	15/16	0.938	0.922	1.083	1.051	25/64	0.403	0.378	1.5	1.75
3/4	0.75	0.75	0.741	1-1/8	1.125	1.1	1.299	1.254	15/32	0.483	0.455	1.75	2
7/8	0.875	0.875	0.866	1-5/16	1.312	1.285	1.516	1.465	35/64	0.563	0.531	2	2.25
1	1	1	0.99	1-1/2	1.5	1.469	1.732	1.675	39/64	0.627	0.591	2.25	2.5
1-1/8	1.125	1.125	1.114	1-11/16	1.688	1.631	1.949	1.859	11/16	0.718	0.658	2.5	2.75
1-1/4	1.25	1.25	1.239	1-7/8	1.875	1.812	2.165	2.066	25/32	0.813	0.749	2.75	3
1-3/8	1.375	1.375	1.363	2-1/16	2.062	1.994	2.382	2.273	27/32	0.878	0.81	3	3.25
1-1/2	1.5	1.5	1.488	2-1/4	2.25	2.175	2.598	2.48	15/16	0.974	0.902	3.25	3.5