1‑1/4"-8 x 4" Stainless Steel 304 B8 Heavy Hex Head Cap Screw, Partial Thread, ASTM A193 Class 1

This 1‑1/4"-8 x 4" heavy hex head cap screw is manufactured from 304 stainless steel and produced in accordance with ASTM A193 Grade B8, Class 1, providing dependable corrosion resistance and mechanical strength for large‑diameter industrial fastening applications. The partial‑thread (PT) design includes a smooth, unthreaded shank section that improves shear capacity and promotes proper alignment in high‑load bolted joints, making it especially effective for flanged connections and thick structural assemblies. The 4" length supports secure fastening through substantial material stacks, while the heavy hex head offers increased bearing surface and enhanced wrench engagement for controlled torque application. Commonly specified for piping systems, pressure equipment, structural steel connections, and heavy fabrication, this fastener delivers reliable resistance to rust, oxidation, and environmental exposure for long‑term performance in indoor, outdoor, and moderately corrosive environments.