ASME B18.2.1 Square Lag Screws

Nominal Size or Basic product Diameter		Body or Shoulder Diameter, E		Width Across Flats, F		Width Across Corners, G		Head Height, H		Minimum Shoulder Length, S	Radius of Fillet, R
Nominal Size or Basic product Diameter		Max.	Min.	Max.	Min.	Max.	Min.	Max.	Min.	Minimum Shoulder Length, S	Max.	Min.
No. 10	0.1900	0.199	0.178	0.281	0.271	0.398	0.372	0.140	0.110	0.094	0.03	0.01
1/4	0.2500	0.260	0.237	0.375	0.362	0.530	0.498	0.188	0.156	0.094	0.03	0.01
5/16	0.3125	0.324	0.298	0.500	0.484	0.707	0.665	0.220	0.186	0.125	0.03	0.01
3/8	0.3750	0.388	0.360	0.562	0.544	0.795	0.747	0.268	0.232	0.125	0.03	0.01
7/16	0.4375	0.452	0.421	0.625	0.603	0.884	0.828	0.316	0.278	0.156	0.03	0.01
1/2	0.5000	0.515	0.482	0.750	0.725	1.061	0.995	0.348	0.308	0.156	0.03	0.01
5/8	0.6250	0.642	0.605	0.938	0.906	1.326	1.244	0.444	0.400	0.312	0.06	0.02
3/4	0.7500	0.768	0.729	1.125	1.088	1.591	1.494	0.524	0.476	0.375	0.06	0.02
7/8	0.8750	0.895	0.852	1.312	1.269	1.856	1.742	0.620	0.568	0.375	0.06	0.02
1	1.0000	1.022	0.976	1.500	1.450	2.121	1.991	0.684	0.628	0.625	0.09	0.03
1 1/8	1.1250	1.149	1.098	1.688	1.631	2.386	2.239	0.780	0.720	0.625	0.09	0.03
1 1/4	1.2500	1.277	1.223	1.875	1.812	2.652	2.489	0.876	0.812	0.625	0.09	0.03

Dimensions of Square Lag Screws