S-91864A081 4-40 x 7/16" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure
• Superior corrosion resistance from the black-oxide finish protects against rust and extends service life in demanding industrial environments
• Precise Class 3A thread fit provides tighter tolerances for secure fastening and vibration resistance in critical assemblies
• High hardness rating (Rockwell C37) maintains thread integrity and prevents stripping during repeated installation and removal cycles
• Compact 3/32" hex drive design allows for easy installation in confined spaces while providing maximum torque transfer
• Full threading along the 7/16" length enables consistent clamping force distribution across the entire engagement area
• Regulatory compliance with ASTM A574, RoHS 3, and REACH ensures material quality and environmental safety for global supply chains

Professional Applications & Engineering Value

These black-oxide alloy steel socket head cap screws deliver critical engineering solutions where space constraints meet high mechanical demands. The 4-40 UNC coarse thread configuration combined with Class 3A thread fit provides superior engagement in softer materials and blind holes, preventing cross-threading while maintaining vibration resistance in dynamic applications. The corrosion-resistant black-oxide surface treatment protects against industrial atmospheres and chemical exposure, making these fully threaded screws ideal for precision equipment, automotive assemblies, and electronic enclosures where reliability cannot be compromised. The 3/32" hex drive interface ensures maximum torque transmission without slippage, even in high-production environments requiring repeated maintenance cycles.

Specification Summary & Compliance

Manufactured to exacting inch system dimensions with Class 3A thread fit tolerances for precision alignment. These socket head cap screws conform to ASTM A574 specification for alloy steel socket head cap screws, ensuring consistent material properties and manufacturing quality. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations guarantees environmental responsibility and unrestricted use in international markets. The right-hand UNC coarse threads provide optimal performance in most industrial fastening applications requiring high strength and durability.