S-90251A112 4-40 x 1/4" ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Superior vibration resistance with nylon patch thread locker that maintains secure fastening in high-stress environments
• Excellent corrosion resistance provided by 18-8 stainless steel construction for extended service life in harsh conditions
• Precise thread engagement with Class 3A fit ensuring reliable performance and consistent clamping force
• Wide temperature tolerance from -50° to 250°F for stable performance across diverse operating environments
• Enhanced installation control through hex drive headless design allowing precise torque application in confined spaces
• Secure component positioning with cup tip design that provides positive contact and prevents slippage
• Industry-standard compliance meeting ASME B18.3 specifications for guaranteed interoperability and quality

Professional Applications & Engineering Value

This 4-40 UNC set screw delivers exceptional engineering value in demanding industrial applications where vibration resistance and precise component positioning are critical. The 18-8 stainless steel construction provides superior corrosion resistance, making it ideal for machinery, automotive assemblies, and electronic enclosures exposed to moisture or chemicals. The nylon patch thread locker effectively prevents loosening under continuous vibration, eliminating the need for secondary locking mechanisms and reducing maintenance costs. The coarse UNC thread design ensures quick installation and reliable holding power in various materials, while the hex headless configuration allows for flush mounting in space-constrained applications. This combination of features addresses common industrial challenges of component creep, corrosion-induced failure, and assembly efficiency.

Specification Summary & Compliance

This precision set screw features Class 3A thread fit for superior dimensional accuracy and consistent performance. Manufactured to ASME B18.3 standards, it ensures reliable mechanical properties and interchangeability. The product maintains full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, containing no restricted substances. The UNC coarse thread with 4-40 specification and 1/4" length provides optimal engagement characteristics for industrial fastening applications requiring high reliability and repeatable performance.