S-91255A038 5/16"-18 x 3 1/2" 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
• High tensile strength (120,000 psi) ensures reliable performance under heavy loads and vibration
• Precision Class 3A thread fit provides superior engagement and reduces cross-threading risks
• Robust Rockwell C39 hardness maintains structural integrity and extends service life
• Hex drive design allows for high-torque installation with standard tools
• Coarse UNC threading enables faster assembly and better performance in softer materials
• Full compliance with ASME B18.3 and ASTM F835 guarantees consistent quality and interchangeability

Professional Applications & Engineering Value

This black-oxide alloy steel hex screw delivers critical performance advantages in demanding applications where corrosion resistance and mechanical strength are paramount. The Class 3A UNC coarse thread configuration ensures rapid, secure fastening in structural assemblies, machinery, and heavy equipment, while the rounded button head profile provides a finished appearance and reduces snagging hazards. Engineered to withstand high-stress conditions, these screws prevent joint failure in vibration-prone environments. The combination of 120,000 psi tensile strength and protective oxide coating makes them ideal for automotive, construction, and industrial manufacturing applications requiring durable, long-lasting fastening solutions.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 3A thread tolerances and UNC coarse threading. Fully compliant with ASME B18.3 and ASTM F835 specifications. Meets environmental regulations including RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance. Thread diameter: 0.313", length: 3-1/2", with right-hand thread direction and fully threaded shank.