S-91306A377 1/4"-20 x 5/8" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc plating, extending service life in harsh industrial environments
• High tensile strength of 120,000 psi ensures reliable performance under heavy loads and vibration
• Precise Class 3A thread fit provides secure fastening with minimal risk of cross-threading or loosening
• Hex drive design allows for high-torque installation with standard tools, reducing assembly time
• Rounded button head profile offers a low-profile, finished appearance while minimizing snagging risks
• Coarse UNC threading enables quick engagement and superior holding power in various materials
• Full threading along the 5/8" length ensures maximum grip and adjustability in deep applications

Professional Applications & Engineering Value

This zinc-plated alloy steel rounded head screw delivers exceptional durability for demanding industrial applications where corrosion resistance and high clamping force are critical. The Class 3A UNC coarse thread provides rapid installation and superior pull-out resistance in metals, plastics, and composite materials, while the hex drive accommodates high torque applications without cam-out. With a Rockwell C39 hardness and 120,000 psi tensile strength, it maintains integrity under dynamic loads, making it ideal for machinery, automotive assemblies, and structural frameworks where vibration resistance and long-term reliability are paramount.

Specification Summary & Compliance

This screw features precise Class 3A thread fit per UNC standards, ensuring dimensional accuracy and interchangeability. Manufacturing complies with ASME B18.3 and ASTM F835 specifications for consistent quality. The product is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for global industrial use.