S-91253A633 3/8"-16 x 2 1/4" 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 environments
• Exceptional tensile strength (130,000 psi) ensures reliable performance under heavy loads and vibration
• Precision Class 3A thread fit provides secure, vibration-resistant fastening with minimal backlash
• 82° countersink angle allows for flush mounting in standard applications, improving aesthetics and safety
• Hex drive (7/32") design enables high-torque installation without cam-out, speeding up assembly
• Partially threaded shank concentrates clamping force where needed, preventing joint loosening
• Rockwell C39 hardness maintains thread integrity and resists wear during repeated use

Professional Applications & Engineering Value

These 3/8"-16 UNC flat head screws with black-oxide alloy steel construction address critical industrial challenges where corrosion resistance and high tensile strength are paramount. The coarse thread spacing and Class 3A thread fit ensure rapid installation and reliable performance in heavy machinery, structural steel assemblies, and automotive components, reducing maintenance downtime. The 82° countersink angle and flat head profile provide a secure, flush finish that eliminates protrusions in confined spaces. Ideal for industrial fastening applications requiring compliance with rigorous standards, these screws deliver consistent clamping force and durability in high-stress environments.

Specification Summary & Compliance

This screw features UNC coarse threads with Class 3A thread fit for precise dimensional accuracy, manufactured to ASME B18.3 and ASTM F835 specifications. It complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use in global markets. The inch-system measurements, including 2 1/4" length and 3/8"-16 thread size, guarantee interchangeability with standard components.