S-91255A050 1/2"-13 x 2 1/4" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with black-oxide coating, ideal for harsh industrial environments
• Superior tensile strength (120,000 psi) prevents stripping and failure under heavy loads
• Precise Class 3A thread fit ensures secure, vibration-resistant connections in critical assemblies
• 5/16" hex drive design provides high torque transmission and reduces tool slippage
• Fully threaded coarse UNC pattern enables faster installation and stronger holding power
• Rounded button head profile offers a low-profile, snag-free finish for safety-sensitive applications
• Compliance with ASME B18.3 and ASTM F835 guarantees consistent quality and interchangeability

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these black-oxide alloy steel button head screws combine high tensile strength (120,000 psi) with Rockwell C39 hardness to withstand extreme mechanical stress and vibration. The coarse UNC threading and fully threaded design ensure rapid assembly in heavy machinery, structural frameworks, and automotive components, while the low-profile rounded head minimizes protrusion risks in confined spaces. Ideal for high-torque hex drive operations, they deliver reliable performance in corrosive environments without compromising on ASME B18.3 and ASTM F835 standards.

Specification Summary & Compliance

This screw adheres to Class 3A thread fit for precise tolerance, with 1/2"-13 UNC coarse threading and a 2-1/4" length. Manufacturing complies with ASME B18.3 and ASTM F835 specifications, and it is fully RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliant for environmental safety.