S-90400A214 4-40 x 1/4" ASME B18.13 Steel Pan Head Phillips Screws with Spring Lock Washer

Key Features & Benefits at a Glance

• Superior vibration resistance with an integrated spring lock washer that maintains tightness under dynamic loads
• Enhanced corrosion protection through zinc-plated steel construction for extended service life in harsh environments
• High tensile strength of 60,000 psi ensures reliable fastening under substantial mechanical stress
• Quick installation and removal with Phillips No. 1 drive and coarse UNC threads for efficient assembly
• Consistent thread engagement with Class 2A fit and full threading for uniform load distribution
• Durable Rockwell B70 hardness provides excellent wear resistance and thread integrity
• Secure pan head design offers a low-profile, rounded head that resists tampering and snagging

Professional Applications & Engineering Value

These 4-40 UNC zinc-plated steel screws deliver critical reliability in industrial applications where vibration loosening is a primary concern. The integrated spring lock washer eliminates the need for separate components, reducing assembly time while providing continuous tension to prevent back-off in machinery, electrical enclosures, and automotive subsystems. The coarse thread design ensures rapid installation in various materials, while the zinc-plated finish combats corrosion in humid or chemically exposed environments. With fully threaded construction and Class 2A thread fit, these pan head screws maintain precise alignment and clamping force, making them ideal for high-cycle production lines and maintenance operations where durability and compliance are non-negotiable.

Specification Summary & Compliance

Manufactured to ASME B18.13 specifications with Class 2A thread fit for consistent dimensional accuracy. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. Features include 4-40 UNC coarse threads, 1/4" length, Rockwell B70 hardness, and 60,000 psi tensile strength.