S-91253A545 1/4"-20 x 1 3/8" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating, extending service life in demanding industrial environments.
• Exceptional tensile strength of 130,000 psi ensures reliable performance under high-stress applications without failure.
• Precise Class 3A thread fit provides secure, vibration-resistant fastening with minimal risk of loosening.
• 82° countersink angle and flat head design allows for flush mounting, reducing snagging and improving aesthetics.
• Hex drive (5/32") compatibility enables easy installation and removal with standard tools, saving assembly time.
• Full threading along the 1 3/8" length offers maximum grip and adjustability in various material thicknesses.
• Compliance with ASTM F835, RoHS 3, and REACH guarantees adherence to rigorous safety and environmental standards.

Professional Applications & Engineering Value

These 1/4"-20 UNC flat head screws are engineered from black-oxide alloy steel to address common industrial challenges like vibration-induced loosening and corrosion. The coarse thread spacing and Class 3A thread fit ensure quick, secure fastening in metals and plastics, reducing assembly errors. Ideal for machinery, automotive, and construction applications, the hex drive and flat head profile facilitate efficient installation in tight spaces, while the high tensile strength and Rockwell C39 hardness prevent stripping and wear, enhancing long-term reliability and reducing maintenance costs.

Specification Summary & Compliance

This product adheres to Class 3A thread fit for precise dimensional accuracy under the UNC thread standard, with a coarse thread spacing and right-hand thread direction. Manufactured in accordance with ASTM F835 specifications, it is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material integrity for global industrial use.