S-91255A565 1/4"-28 x 5/16" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with Black-Oxide coating that protects against rust in demanding industrial environments
• Exceptional tensile strength of 120,000 psi ensures reliable performance under high-stress applications
• Precision Class 3A thread fit provides tighter tolerances for secure fastening in critical assemblies
• Full threading design maximizes engagement strength across the entire fastener length
• Hex drive compatibility with 5/32" drive size enables efficient installation with standard tools
• Rounded button head profile offers a low-profile finish that reduces snagging hazards
• High hardness rating of Rockwell C39 ensures excellent wear resistance and durability

Professional Applications & Engineering Value

These Black-Oxide Alloy Steel rounded head hex screws deliver exceptional performance in precision engineering applications where vibration resistance and reliable clamping force are critical. The 1/4"-28 UNF fine thread configuration with Class 3A fit provides superior engagement in tapped holes, preventing loosening in dynamic environments. The combination of 120,000 psi tensile strength and Rockwell C39 hardness ensures these fasteners maintain integrity in high-stress assemblies, while the Black-Oxide surface treatment offers corrosion protection without compromising dimensional accuracy. Ideal for machinery, automotive, and industrial equipment where precision screws must withstand cyclic loading and harsh operating conditions.

Specification Summary & Compliance

Manufactured to exacting standards with Class 3A thread tolerances and UNF fine thread specifications. These fully threaded screws comply with ASME B18.3 and ASTM F835 manufacturing standards, ensuring consistent quality and dimensional accuracy. The products are RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting international environmental regulations for industrial components.