S-91253A646 3/8"-16 x 4 1/2" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional durability with 130,000 psi tensile strength and Rockwell C39 hardness for reliable performance in demanding applications
• Superior corrosion resistance through black-oxide coating on alloy steel, extending service life in harsh industrial environments
• Precise thread engagement with Class 3A fit and UNC coarse threads ensuring secure fastening and vibration resistance
• Optimized installation efficiency featuring 7/32" hex drive for positive torque transmission and reduced tool slippage
• Flush mounting capability with 82° countersink angle and standard flat head profile for smooth surface finishes
• Reduced weight and material usage through partially threaded design while maintaining full grip length requirements
• Regulatory compliance assurance meeting ASTM F835 specifications and international environmental standards

Professional Applications & Engineering Value

These 3/8"-16 UNC flat head screws deliver critical engineering solutions for industrial equipment assembly and heavy-duty machinery applications. The black-oxide alloy steel construction provides superior protection against corrosion and wear, while the Class 3A thread fit ensures precise engagement in high-vibration environments. The partially threaded design concentrates strength where needed most, reducing weight without compromising structural integrity. With 130,000 psi tensile strength and Rockwell C39 hardness, these hex drive screws withstand extreme mechanical stresses in construction, manufacturing, and automotive applications where reliability is paramount.

Specification Summary & Compliance

Manufactured to exacting Class 3A thread fit tolerances with UNC coarse threading (3/8"-16) and 4 1/2" length with minimum 1 1/4" thread engagement. Compliant with ASTM F835 specifications for mechanical properties and dimensional requirements. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global industrial markets. Features standard 82° countersink angle and 7/32" hex drive for consistent installation performance.