Hex socket cap screws with UNC thread according to ANSI B18.3 standard. The design corresponds closely to ISO 4762 with a cylindrical head but uses Unified National Coarse (UNC) inch threads instead of metric. UNC threads are commonly used in machinery, imported equipment, and industrial assemblies where inch threads are standard. The SWEBOLT & BOTNIA BOLT range includes strength classes 8.8 (zinc plated) and 12.9 (plain) for general and high-strength applications.