S-91375A871 7/8"-9 x 7/8" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Exceptional holding power with Class 3A thread fit for secure, vibration-resistant fastening in demanding applications
• Superior corrosion resistance provided by black-oxide coating on alloy steel, extending service life in harsh environments
• High-strength durability with Rockwell C45 hardness rating, maintaining structural integrity under heavy loads
• Secure installation and removal through 1/2" hex drive design, allowing high torque application without stripping
• Precise component positioning with cup tip design that creates consistent contact points without damaging mating surfaces
• Reliable coarse threading (UNC 7/8"-9) for faster installation and reduced cross-threading risks in industrial assemblies
• Space-saving headless design enabling flush mounting where clearance is limited or rotating components are present

Professional Applications & Engineering Value

This black-oxide alloy steel set screw delivers critical engineering solutions for industrial applications requiring permanent component positioning. The Class 3A thread fit ensures precise engagement with mating parts, eliminating play in pulley systems, gear assemblies, and shaft collars. The cup tip design concentrates clamping force while minimizing surface marring, ideal for precision machinery where component alignment is paramount. With Rockwell C45 hardness and coarse UNC threading, this fastener maintains clamping force under extreme vibration and load conditions common in manufacturing equipment, automotive systems, and heavy machinery. The 1/2" hex drive accommodates standard industrial tools for efficient installation in confined spaces where headless fasteners are specified.

Specification Summary & Compliance

This precision set screw features 7/8"-9 UNC coarse threads with Class 3A thread fit for superior dimensional accuracy and engagement. Manufacturing complies with ASME B18.3 specifications where identified as ASTM F912, ensuring consistent quality and performance. The product is RoHS 3 (2015/863/EU) Compliant, meeting environmental regulations for hazardous substance restrictions. Thread diameter measures 0.875" with right-hand thread direction and 7/8" length for standardized industrial applications.