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

Manufactured from 316 stainless steel and compliant with ASTM A193 Grade B8M, Class 1, the 1"-8 x 4‑1/4" heavy hex head cap screw is engineered for corrosion‑resistant fastening in high‑stress industrial and structural applications. The partial‑thread (PT) configuration incorporates an extended unthreaded shank that improves shear strength and promotes efficient load transfer across bolted joints, making it particularly effective for flanged connections and thick material assemblies. Its 4‑1/4" length provides added reach for deeper engagement, while the heavy hex head offers increased bearing surface and enhanced wrench engagement for accurate, controlled torque application. 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.