S-91375A821 5/8"-18 x 1 3/4" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide finish, extending service life in demanding industrial environments
• Precise Class 3A thread fit ensures tight, secure fastening with minimal backlash in critical assemblies
• High-strength alloy steel construction with Rockwell C45 hardness provides excellent wear resistance and load-bearing capacity
• Cup tip design creates positive engagement and prevents component slippage during high-torque applications
• Headless hex drive configuration allows for flush installation in space-constrained applications
• Fine UNF thread profile delivers superior vibration resistance and improved clamping force distribution
• Full regulatory compliance with ASME B18.3, RoHS 3, and REACH standards for global industrial acceptance

Professional Applications & Engineering Value

This black-oxide alloy steel set screw delivers exceptional performance in precision machinery, automotive systems, and heavy equipment applications where vibration resistance and corrosion protection are critical. The 5/8"-18 UNF fine thread configuration with Class 3A fit provides superior holding power in high-stress assemblies, while the cup tip design ensures positive seating without damaging mating surfaces. The headless hex drive configuration enables clean, flush installations in tight spaces, making it ideal for shaft collars, gears, and pulley systems requiring reliable positioning without protrusion.

Specification Summary & Compliance

Manufactured to exacting ASME B18.3 specifications with Class 3A thread fit precision and Rockwell C45 hardness rating. Features 5/8"-18 UNF fine threads with right-hand direction and 5/16" hex drive configuration. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations for unrestricted industrial use worldwide.