S-91253A626 3/8"-16 x 1 1/4" 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 applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish on alloy steel, extending service life in demanding industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies with minimal backlash.
• Fully threaded design offers maximum grip and load distribution along the entire length, enhancing joint integrity.
• 82° countersink angle allows for a flush, low-profile installation, improving aesthetics and safety in assembled products.
• Hex drive (7/32") enables high-torque installation with common tools, speeding up assembly and reducing labor time.
• Rockwell C39 hardness ensures excellent wear resistance and durability, maintaining performance over repeated use.

Professional Applications & Engineering Value

Engineered for demanding industrial settings, these 3/8"-16 UNC flat head screws with black-oxide alloy steel construction address critical challenges like vibration loosening and environmental exposure. The coarse UNC threading and Class 3A fit provide superior holding power in metals and plastics, minimizing the need for frequent retightening in machinery, automotive frames, and structural assemblies. The fully threaded design ensures consistent clamping force, while the 82° countersink facilitates seamless integration into angled surfaces, reducing protrusion risks. Ideal for heavy-duty fastening in construction, manufacturing, and equipment repair, these screws deliver long-term reliability under dynamic loads and harsh conditions.

Specification Summary & Compliance

This screw features a 3/8"-16 UNC coarse thread with Class 3A thread fit for high precision, and is manufactured to meet ASME B18.3 and ASTM F835 standards. It complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material reliability in global supply chains.