S-91274A198 1"-8 x 3" ASME B18.3, ASTM A574, ASTM B117 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance with zinc-flake coating protects against harsh industrial environments, extending service life and reducing maintenance costs.
• Precise Class 3A thread fit guarantees secure, vibration-resistant connections, minimizing loosening in dynamic operations.
• High hardness (Rockwell C37) provides excellent wear resistance, maintaining thread integrity through repeated installations.
• 3/4" hex drive design allows for high-torque installation with standard tools, speeding up assembly and reducing labor time.
• Partially threaded shank offers optimal grip and clamping force control, ideal for components requiring precise alignment.
• Compliance with ASME B18.3 and ASTM A574 ensures consistent quality and interchangeability, simplifying procurement and inventory management.

Professional Applications & Engineering Value

Engineered for demanding industrial settings, these socket head cap screws deliver robust performance in heavy machinery, automotive assemblies, and structural frameworks. The zinc-flake-coated alloy steel construction combats corrosion in humid or chemically aggressive environments, while the 1"-8 UNC coarse thread facilitates quick assembly and disassembly without compromising holding power. With a right-hand thread direction and standard socket head profile, they provide reliable torque transmission and accessibility in confined spaces. This combination of high tensile strength and corrosion resistance addresses common failure points, ensuring long-term operational reliability and reduced downtime in critical applications.

Specification Summary & Compliance

This screw features a Class 3A thread fit for precise engagement, adhering to UNC coarse thread standards with a 1"-8 thread size and 2 1/2" minimum thread length. Manufactured in compliance with ASME B18.3 and ASTM A574 specifications, it ensures dimensional accuracy and mechanical consistency. The product is fully RoHS 3 (2015/863/EU) compliant and REACH (EC 1907/2006) compliant, meeting environmental and safety regulations for global industrial use.