S-91385A586 5/16"-18 x 2" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Permanent vibration resistance with nylon patch thread locker that maintains integrity from -50°F to 250°F
• Superior corrosion protection through black-oxide coating on alloy steel for extended service life
• Precise thread engagement with Class 3A fit ensuring reliable fastening in demanding applications
• High-strength construction with Rockwell C45 hardness providing exceptional durability under load
• Secure installation capability through hex drive design allowing high torque application without head interference
• Optimized gripping performance with cup tip design distributing pressure evenly on contacted surfaces
• Industry-standard compatibility with UNC coarse threads meeting ASME B18.3 specifications

Professional Applications & Engineering Value

This black-oxide alloy steel set screw delivers critical performance in industrial assemblies where vibration-induced loosening threatens operational safety. The permanent nylon patch thread locker creates a chemical bond that withstands extreme temperature fluctuations from -50°F to 250°F, eliminating the need for secondary locking mechanisms. Engineered with Class 3A thread fit and UNC coarse threading, it ensures precise engagement in pulleys, gears, and collars while the cup tip design provides superior gripping force without damaging shaft surfaces. The headless configuration with hex drive enables flush mounting in space-constrained applications, making it ideal for machinery, automotive, and heavy equipment where reliability is paramount.

Specification Summary & Compliance

Manufactured to ASME B18.3 standards with Class 3A thread fit precision, this 5/16"-18 UNC set screw features coarse thread spacing and right-hand thread direction. The assembly meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance requirements, ensuring environmental regulatory adherence for global industrial applications. Specifications include 2" length, 5/32" hex drive size, and Rockwell C45 hardness rating for consistent performance across manufacturing and maintenance operations.