S-90117A587 5/16"-18 x 1 1/2" ASME B18.3 Alloy Steel Wire-Lockable Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength (170,000 PSI) ensures reliable performance in high-stress industrial environments
• Superior corrosion resistance through black-oxide coating extends service life in demanding conditions
• Precision Class 3A thread fit provides secure fastening with minimal play in critical assemblies
• High hardness rating (Rockwell C37) maintains structural integrity under repeated loading
• Wire locking capability prevents accidental loosening in vibrating machinery applications
• Coarse UNC threading enables quick installation and removal in maintenance operations
• Standard hex drive compatibility allows for easy torque application with common tools

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw delivers critical engineering solutions where precision and durability are paramount. The combination of 170,000 PSI tensile strength and Rockwell C37 hardness makes it ideal for heavy machinery, automotive assemblies, and industrial equipment subjected to extreme mechanical stresses. The Class 3A thread fit ensures tight tolerances for vibration-resistant connections, while the black-oxide surface treatment provides essential corrosion protection in harsh operating environments. The 5/16"-18 UNC coarse thread design facilitates rapid assembly in production lines, and the wire locking feature maintains fastener integrity in applications prone to shock and vibration. These socket head cap screws are engineered to meet the rigorous demands of manufacturing, construction, and maintenance operations where failure is not an option.

Specification Summary & Compliance

This fastener maintains Class 3A thread fit precision according to UNC coarse thread standards with exact dimensional compliance to ASME B18.3 specifications. The manufacturing process ensures consistent thread diameter of 0.3125" and proper coarse thread spacing for reliable performance. Full regulatory compliance is verified with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards, making these screws suitable for global industrial applications requiring certified components.