ASME B18.2.1 Square Bolts

                                                                                                                                                        

Nominal Size or Basic Product Diameter		Full-Size Body Diameter, E (See Paras. 3.4 and 3.5)		Width Across Flats, F (See Para. 2.1.2)			Width Across Corners, G		Head Height, H			Radius of Fillet, R		Thread Length for Bolt Lengths, LT (See Para. 3.7)
														6 in. and Shorter	Over 6 in.
		Max.	Min.	Basic	Max.	Min.	Max.	Min.	Basic	Max.	Min.	Max.	Min.	Nom.	Nom.
ASME B18.2.1 - 1⁄4	0.2500	0.260	0.237	3⁄8	0.375	0.362	0.53	0.498	11⁄64	0.188	0.156	0.03	0.01	0.750	1.000
ASME B18.2.1 - 5⁄16	0.3125	0.324	0.298	1⁄2	0.500	0.484	0.707	0.665	13⁄64	0.220	0.186	0.03	0.01	0.875	1.125
ASME B18.2.1 - 3⁄8	0.3750	0.388	0.360	9⁄16	0.562	0.544	0.795	0.747	1⁄4	0.268	0.232	0.03	0.01	1.000	1.250
ASME B18.2.1 - 7⁄16	0.4375	0.452	0.421	5⁄8	0.625	0.603	0.884	0.828	19⁄64	0.316	0.278	0.03	0.01	1.125	1.375
ASME B18.2.1 - 1⁄2	0.5000	0.515	0.482	3⁄4	0.750	0.725	1.061	0.995	21⁄64	0.348	0.308	0.03	0.01	1.250	1.500
ASME B18.2.1 - 5⁄8	0.6250	0.642	0.605	15⁄16	0.938	0.906	1.326	1.244	27⁄64	0.444	0.400	0.06	0.02	1.500	1.750
ASME B18.2.1 - 3⁄4	0.7500	0.768	0.729	11⁄8	1.125	1.088	1.591	1.494	1⁄2	0.524	0.476	0.06	0.02	1.750	2.000
ASME B18.2.1 - 7⁄8	0.8750	0.895	0.852	15⁄16	1.312	1.269	1.856	1.742	19⁄32	0.620	0.568	0.06	0.02	2.000	2.250
ASME B18.2.1 - 1	1.0000	1.022	0.976	11⁄2	1.500	1.45	2.121	1.991	21⁄32	0.684	0.628	0.09	0.03	2.250	2.500
ASME B18.2.1 - 1 1⁄8	1.1250	1.149	1.098	111⁄16	1.688	1.631	2.386	2.239	3⁄4	0.780	0.720	0.09	0.03	2.500	2.750
ASME B18.2.1 - 1 1⁄4	1.2500	1.277	1.223	17⁄8	1.875	1.812	2.652	2.489	27⁄32	0.876	0.812	0.09	0.03	2.750	3.000
ASME B18.2.1 - 1 3⁄8	1.3750	1.404	1.345	21⁄16	2.062	1.994	2.917	2.738	29⁄32	0.940	0.872	0.09	0.03	3.000	3.250
ASME B18.2.1 - 1 1⁄2	1.5000	1.531	1.470	21⁄4	2.250	2.175	3.182	2.986	1	1.036	0.964	0.09	0.03	3.250	3.500
GENERAL NOTE: Refer to section 3 for further information.