S-91253A953 1/2"-20 x 6" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 130,000 psi for reliable performance in high-stress industrial applications.
• Precise Class 3A thread fit ensures superior engagement and vibration resistance in critical assemblies.
• Alloy steel construction with Rockwell C39 hardness provides excellent durability and wear resistance.
• 5/16" hex drive offers secure, high-torque installation without cam-out for efficient assembly.
• 82° countersink angle allows for a flush, professional finish in countersunk holes.
• Partial threading enables focused clamping force where needed along the 6" length.
• Compliance with ASTM F835, RoHS 3, and REACH guarantees material quality and environmental safety.

Professional Applications & Engineering Value

This 1/2"-20 UNF flat head screw is engineered for heavy-duty industrial fastening where reliability is non-negotiable. The alloy steel material, combined with Rockwell C39 hardness, resists deformation under load, making it ideal for machinery, structural frames, and equipment subjected to dynamic stresses. The fine UNF thread and Class 3A fit provide superior holding power in tapped holes, reducing the risk of loosening in vibrating environments. With a partially threaded design, it concentrates clamping force precisely, while the hex drive ensures straightforward installation in confined spaces. These features address common engineering challenges like joint integrity, ease of assembly, and long-term performance in demanding industrial applications.

Specification Summary & Compliance

This screw adheres to Class 3A thread fit for high precision and meets ASTM F835 specifications for mechanical properties. It is manufactured with a right-hand UNF fine thread (1/2"-20) and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safety and quality for industrial use.