S-90251A183 1/4"-20 x 3/8" ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Secure vibration-resistant locking with nylon patch thread locker that maintains integrity across a wide temperature range from -50°F to 250°F
• Superior corrosion resistance in harsh environments thanks to 316 stainless steel construction
• Precise thread engagement with Class 3A thread fit ensuring reliable, tight fastening in critical applications
• High torque capability through hex drive design allowing for secure installation without head protrusion
• Excellent durability with Rockwell B80 hardness providing long service life in demanding conditions
• Optimized grip performance with cup tip design that creates secure contact points on mating surfaces
• Industry-standard compatibility with UNC coarse threads for easy replacement and broad application use

Professional Applications & Engineering Value

This 316 stainless steel set screw with nylon patch locking technology addresses critical challenges in industrial fastening where vibration loosening and environmental exposure compromise joint integrity. The headless design with hex drive provides flush mounting in confined spaces while delivering high torque transmission. Engineered with UNC coarse threads and Class 3A fit, it ensures precise engagement in machinery, automotive components, and precision equipment. The cup tip configuration creates concentrated pressure points that prevent slippage in shaft collars, pulleys, and gear assemblies. With exceptional corrosion resistance from 316 stainless steel, this locking set screw maintains performance in chemical processing, marine, and high-humidity applications where fastener failure is not an option.

Specification Summary & Compliance

This set screw features 1/4"-20 UNC coarse threads with Class 3A thread fit for precision tolerance, measuring 3/8" in length with 1/8" hex drive. Manufactured to ASME B18.3 specifications, it ensures dimensional accuracy and performance reliability. The product is fully RoHS 3 (2015/863/EU) compliant and REACH (EC 1907/2006) compliant, meeting international environmental standards for restricted substances. The nylon patch thread locker provides consistent locking performance across the specified temperature range while maintaining regulatory compliance.