S-91253A535 1/4"-20 x 3/8" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 130,000 psi ensures reliable performance in high-stress industrial applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish on alloy steel extends service life in demanding environments, minimizing maintenance needs.
• Precise Class 3A thread fit with UNC coarse threading provides secure, vibration-resistant connections for improved assembly integrity.
• 82° countersink angle allows for a flush, low-profile installation, enhancing aesthetics and preventing snagging in machinery.
• Hex drive design (5/32") offers easy installation and removal with standard tools, boosting efficiency in maintenance and production lines.
• Full threading ensures consistent grip along the entire length, delivering uniform clamping force for stable joints.
• Compliance with ASME B18.3 and ASTM F835 guarantees adherence to industry standards, ensuring compatibility and safety in regulated sectors.

Professional Applications & Engineering Value

Engineered for rigorous industrial use, these black-oxide alloy steel flat head screws address common fastening challenges such as vibration loosening and corrosion in machinery, automotive, and construction assemblies. The UNC coarse thread and Class 3A fit provide superior holding power in coarse-grained materials, reducing the need for frequent retightening. With a Rockwell C39 hardness and robust 130,000 psi tensile strength, they withstand heavy loads and harsh conditions, while the 82° countersink ensures seamless integration into countersunk holes for streamlined surfaces. Ideal for applications requiring RoHS 3 and REACH compliance, these screws offer reliability in electronics, industrial equipment, and other sectors where environmental regulations and durability are critical.

Specification Summary & Compliance

This screw features precise inch system measurements with a 1/4"-20 UNC coarse thread and Class 3A thread fit for tight tolerances. It adheres to ASME B18.3 and ASTM F835 specifications, ensuring consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting use in environmentally conscious industries without hazardous substances.