S-91375A540 1/4"-20 x 3/4" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating that protects against rust and extends service life in harsh industrial environments
• Exceptional thread engagement with Class 3A fit ensuring precise, vibration-resistant fastening for critical assemblies
• High-torque installation capability through 1/8" hex drive design that prevents stripping and enables secure tightening
• Optimized material strength with Rockwell C45 hardness providing reliable performance under heavy mechanical stress
• Effective component positioning via cup tip design that creates positive locking action on shafts and axles
• Simplified installation with right-hand coarse UNC threads that enable quick assembly and disassembly
• Industry-standard compliance meeting ASME B18.3 specifications for consistent quality and interchangeability

Professional Applications & Engineering Value

This black-oxide alloy steel set screw delivers critical engineering solutions for industrial applications where vibration resistance and positional accuracy are paramount. The Class 3A thread fit provides tighter tolerances than standard fasteners, eliminating play in precision machinery, automotive components, and power transmission systems. The cup tip design concentrates pressure on a small contact area, creating superior holding power against rotational forces on shafts, collars, and gears. With Rockwell C45 hardness, these headless set screws maintain their structural integrity under repeated stress cycles, while the coarse UNC 1/4"-20 threads ensure rapid installation in production environments. The black-oxide surface treatment provides an additional layer of corrosion protection, making these industrial set screws suitable for applications exposed to moisture and industrial chemicals.

Specification Summary & Compliance

This set screw features precision 1/4"-20 UNC coarse threads with Class 3A fit for superior thread engagement and vibration resistance. Manufacturing complies with ASME B18.3 specifications (ASTM F912) ensuring dimensional accuracy and performance reliability. The product is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting current environmental regulations for industrial fasteners.