ASME B18.2.1 Square Lag Screws

Dimensions of Square Lag Screws

Nominal Size or Basic product DiameterBody or Shoulder Diameter, EWidth Across Flats, FWidth Across Corners, GHead Height, HMinimum Shoulder Length, SRadius of Fillet, R
Max.Min.Max.Min.Max.Min.Max.Min.Max.Min.
No. 100.19000.1990.1780.2810.2710.3980.3720.1400.1100.0940.030.01
1/40.25000.2600.2370.3750.3620.5300.4980.1880.1560.0940.030.01
5/160.31250.3240.2980.5000.4840.7070.6650.2200.1860.1250.030.01
3/80.37500.3880.3600.5620.5440.7950.7470.2680.2320.1250.030.01
7/160.43750.4520.4210.6250.6030.8840.8280.3160.2780.1560.030.01
1/20.50000.5150.4820.7500.7251.0610.9950.3480.3080.1560.030.01
5/80.62500.6420.6050.9380.9061.3261.2440.4440.4000.3120.060.02
3/40.75000.7680.7291.1251.0881.5911.4940.5240.4760.3750.060.02
7/80.87500.8950.8521.3121.2691.8561.7420.6200.5680.3750.060.02
11.00001.0220.9761.5001.4502.1211.9910.6840.6280.6250.090.03
1 1/81.12501.1491.0981.6881.6312.3862.2390.7800.7200.6250.090.03
1 1/41.25001.2771.2231.8751.8122.6522.4890.8760.8120.6250.090.03