S-91385A352 1/4"-28 x 5/16" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Superior vibration resistance through integrated nylon patch thread locker that maintains secure fastening in high-stress environments
• Exceptional temperature stability with thread locker performing reliably from -50°F to 250°F for demanding industrial applications
• Precision Class 3A thread fit ensures tight tolerances and secure engagement for maximum holding power in critical assemblies
• Enhanced corrosion protection from black-oxide coating on alloy steel, extending service life in various operating conditions
• Optimized torque transmission with 1/8" hex drive design that prevents tool slippage and ensures consistent installation
• Secure point contact through cup tip design that digs into mating surfaces for positive positioning and anti-rotation performance
• High strength durability with Rockwell C45 hardness rating that withstands heavy loads and repeated use without deformation

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel set screw delivers critical engineering solutions where vibration-induced loosening compromises assembly integrity. The integrated Nylon Patch thread locker creates permanent friction that eliminates back-off in rotating equipment, machinery, and precision instruments. Engineered with UNF fine threads and Class 3A fit, it provides superior clamping force in limited-space applications while the cup point design bites into shafts and collars for positive mechanical locking. The headless configuration with 1/8" hex drive enables flush mounting in confined areas, making it ideal for precision alignment fixtures, gear assemblies, and coupling applications where reliability under dynamic loads is paramount.

Specification Summary & Compliance

Manufactured to ASME B18.3 specifications with UNF 1/4"-28 fine threads and precision Class 3A thread fit for exacting dimensional requirements. The Black-Oxide Alloy Steel construction provides corrosion resistance while maintaining Rockwell C45 hardness for durability. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global industrial markets. Thread locker performance validated from -50°F to 250°F temperature range.