Visit our Investor website
Overview

Unified Socket Head Cap Screws

ANSI/ASME B18.3.2003

Materials and Finishes:  

Steel 12.9/Self colour 

Stainless steel/Self colour

Note: Due to the fact that fastening applications differ greatly, the below information is for guidance only and is correct to the best of our knowledge. The customer must satisfy themselves with the performance of the fastener and validity of the data. TR Fastenings will not be held responsible for any failure that may occur from the use of this information.

Dimension data
d (thread size)D maxH maxS (Key Size)t min
UNF 4.48UNC 4.400.1830.1123/320.0940.051
UNF 6.40UNC 6.320.0260.1387/640.1090.064
UNF 8.36UNC 8.320.2700.1649/640.1410.077
UNF 10.32UNC 10.240.3120.1905/320.1560.090
1/4 UNF1/4 UNC0.3750.2503/160.1880.120
5/16 UNF5/16 UNC0.4690.3121/40.2500.151
3/8 UNF3/8 UNC0.5620.3755/160.3120.182
7/16 UNF7/16 UNC0.6560.4383/80.3750.213
1/2 UNF1/2 UNC0.7500.5003/80.3750.245
5/8 UNF5/8 UNC0.9380.6251/20.5000.307
3/4 UNF3/4 UNC1.1250.7505/80.6250.370
7/8 UNF7/8 UNC1.3120.8753/40.7500.432
1 UNF1 UNC1.5001.0003/40.7500.496
1.1/8 UNF1.1/8 UNC1.6881.1257/80.8750.557
1.1/4 UNF1.1/4 UNC1.8751.2507/80.8750.620

 

Technical Support Articles
UNC thread sizes
UNF thread sizes
Tightening factors & tolerances