S-90251A167 4-40 x 1/8" ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with permanent Nylon Patch thread locker that maintains secure fastening even under dynamic loads
• Superior corrosion resistance thanks to 316 Stainless Steel construction, ideal for harsh environments and chemical exposure
• Precision thread engagement with Class 3A fit ensuring reliable, consistent performance in critical applications
• Wide temperature tolerance from -50° to 250°F (-45° to 121°C) for stable performance across diverse operating conditions
• Space-saving headless design with hex drive for flush mounting where clearance is limited
• Enhanced grip capability with cup tip design that bites into mating surfaces for superior anti-rotation security
• Industry-standard compliance meeting ASME B18.3 specifications for guaranteed dimensional accuracy and performance

Professional Applications & Engineering Value

This 4-40 UNC Class 3A set screw delivers exceptional engineering value in applications where vibration resistance and corrosion protection are critical. The Nylon Patch locking technology provides permanent thread locking without compromising disassembly capability, solving common loosening issues in machinery, automotive, and aerospace components. Manufactured from 316 Stainless Steel, it offers superior resistance to chlorides and acidic environments compared to standard stainless grades. The headless hex drive design allows for flush installation in tight spaces while maintaining high torque capability. With its coarse UNC threads and cup tip configuration, this fastener ensures maximum holding power in pulleys, gears, and collars where rotational forces are present.

Specification Summary & Compliance

This precision fastener features 4-40 UNC Class 3A threads with coarse thread spacing and right-hand direction, ensuring optimal engagement and load distribution. The 1/8" length and 0.050" hex drive provide consistent installation across applications. Manufactured to ASME B18.3 standards with Rockwell B80 hardness for durability. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, making it suitable for global industrial applications requiring strict material compliance.