1"-8 x 4‑1/2" Stainless Steel 316 B8M Heavy Hex Head Cap Screw, Partial Thread, ASTM A193 Class 1

Manufactured from 316 stainless steel and certified to ASTM A193 Grade B8M, Class 1, the 1"-8 x 4‑1/2" heavy hex head cap screw is engineered for demanding industrial and structural fastening applications requiring superior corrosion resistance. The partial‑thread (PT) design incorporates an extended unthreaded shank that enhances shear strength and promotes proper load transfer in high‑stress bolted joints, particularly in flanged connections and thick material assemblies. The heavy hex head provides increased bearing surface and improved wrench engagement, allowing controlled torque application during installation. Commonly used in marine environments, chemical processing equipment, pressure assemblies, and outdoor structural applications, this fastener delivers dependable performance and long service life in corrosive and moisture‑exposed conditions.