S-91255A830 3-48 x 5/16" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with Black-Oxide finish, extending service life in demanding industrial environments
• Precision Class 3A thread fit ensures secure, vibration-resistant fastening with minimal backlash
• High tensile strength (120,000 psi) provides reliable performance under extreme mechanical stress
• Rockwell C39 hardness maintains thread integrity and prevents stripping during repeated installations
• 1/16" hex drive design enables quick installation with standard tools while preventing cam-out
• Fully threaded UNC coarse pattern delivers faster assembly and superior holding power in various materials
• Rounded button head profile offers a low-profile, snag-free finish for safety-critical applications

Professional Applications & Engineering Value

Engineered for precision assembly requirements, these Black-Oxide Alloy Steel screws solve critical fastening challenges in industrial equipment, electronics enclosures, and precision machinery. The 3-48 UNC Class 3A thread specification provides exceptional dimensional accuracy for components requiring tight tolerances, while the coarse thread design ensures rapid installation in both metallic and composite materials. The combination of 120,000 psi tensile strength and Rockwell C39 hardness addresses vibration-induced loosening and material fatigue in high-cycle applications. The rounded head with hex drive configuration allows for flush mounting in confined spaces while maintaining tool accessibility, making these fully threaded screws ideal for OEM manufacturing and maintenance operations where reliability and compliance are paramount.

Specification Summary & Compliance

Manufactured to exacting Class 3A thread tolerances with UNC coarse threading (3-48 size), these screws meet ASME B18.3 and ASTM F835 specifications for dimensional consistency and mechanical performance. The 5/16" length and 0.188" head diameter maintain precise engineering standards. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations ensures environmental responsibility and workplace safety, making them suitable for global industrial applications requiring certified components.