S-91253A640 3/8"-16 x 3 1/2" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with black-oxide coating protecting against rust in demanding industrial environments
• Superior tensile strength of 130,000 psi ensures reliable performance in high-stress applications
• Precise Class 3A thread fit delivers superior engagement and vibration resistance in critical assemblies
• Optimal flush mounting with 82° countersink angle and standard flat head profile for seamless surface finishing
• Enhanced driving efficiency with 7/32" hex drive providing secure torque transmission and reduced cam-out
• Reliable partial threading design allows for controlled clamping force and precise joint compression
• Full regulatory compliance with ASTM F835, RoHS 3, and REACH standards for global industrial applications

Professional Applications & Engineering Value

These 3/8"-16 UNC flat head screws deliver critical engineering solutions where surface flushness and high-strength fastening intersect. The black-oxide alloy steel construction provides superior corrosion protection while maintaining Rockwell C39 hardness for exceptional wear resistance in repetitive assembly operations. The coarse UNC threading ensures rapid installation in structural steel, heavy machinery, and industrial equipment where vibration resistance is paramount. The partially threaded design concentrates clamping force precisely where needed, preventing joint loosening in high-vibration environments. These industrial screws are engineered to withstand extreme mechanical stresses while maintaining dimensional stability, making them ideal for construction equipment, agricultural machinery, and transportation applications where reliability cannot be compromised.

Specification Summary & Compliance

Manufactured to exacting Class 3A thread fit tolerances with UNC coarse threading (3/8"-16) and 82° countersink angle for precise flush mounting. These flat head screws comply with ASTM F835 specifications for mechanical properties and dimensional requirements. The fasteners are fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use in global industrial markets. The 3 1/2" length with 1 1/4" minimum thread length provides optimal engagement depth for secure fastening in various material thicknesses.