1"-8 x 4" Stainless Steel 316 B8M Heavy Hex Head Cap Screw, Partial Thread, ASTM A193 Class 1

Manufactured from 316 stainless steel and produced in accordance with ASTM A193 Grade B8M, Class 1, the 1"-8 x 4" heavy hex head cap screw is designed for corrosion‑resistant fastening in demanding industrial and structural applications. The partial‑thread (PT) design features an unthreaded shank section that enhances shear strength and ensures efficient load transfer across high‑stress bolted joints, making it well suited for flanged connections and thick material assemblies. Its 4" length provides ample grip for secure engagement, while the heavy hex head offers increased bearing surface and improved wrench engagement for controlled, high‑torque installation. Commonly specified for marine environments, chemical processing equipment, pressure systems, and outdoor structural assemblies, this fastener delivers dependable performance and long service life in corrosive and moisture‑exposed conditions.