Square Head Dimensions

Bolt DiameterDFCH
Body DiameterWidth Across FlatsWidth Across CornersHeight
MaxBasicMaxMinMaxMinBasicMaxMin
120.515340.7500.7251.0610.99521640.3480.308
580.64215160.9380.9061.3261.24427640.4440.400
340.7681181.1251.0881.5911.494120.5240.476
780.89515161.3121.2691.8561.74219320.6200.568
11.0221121.5001.4502.1211.99121320.6840.628
1181.149111161.6881.6312.3862.239340.7800.720
1141.2771781.8751.8122.6522.48927320.8760.812
1381.40421162.0621.9942.9172.73829320.9400.872
1121.5312142.2502.1753.1822.98611.0360.964
134*29161316
2*215161516

* ASME only defines head dimensions up to 1-1/2". Dimensions for 1-3/4 and 2" are approximate and not covered under the ASME dimensional specifications.

Dimensions per ASME B18.2.1 1996