S-91255A529 1/4"-20 x 2 3/4" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 120,000 PSI ensures reliable performance under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Class 3A thread fit provides superior precision and tighter tolerances for secure, vibration-resistant assemblies in critical machinery and equipment.
• Black-oxide coating on alloy steel offers enhanced corrosion resistance and durability, extending service life in harsh industrial environments.
• Hex drive design allows for easy installation and high torque application, minimizing slippage and improving assembly efficiency.
• Coarse UNC threading ensures quick engagement and strong holding power, ideal for rapid assembly and disassembly operations.
• Rounded button head profile provides a low-profile, aesthetically clean finish while reducing the risk of snagging or injury in exposed applications.
• Full threading along the 2-3/4" length offers maximum grip and adjustability, accommodating various material thicknesses with consistent clamping force.

Professional Applications & Engineering Value

This black-oxide alloy steel rounded head screw is engineered to address common industrial challenges such as vibration loosening, corrosion, and high mechanical stress. The combination of Class 3A UNC coarse threads and hex drive ensures precise, secure fastening in heavy machinery, automotive assemblies, and construction equipment, where reliability is critical. The 120,000 PSI tensile strength and Rockwell C39 hardness provide exceptional resistance to shear and tensile forces, making it suitable for structural applications. Its black-oxide surface treatment not only enhances corrosion resistance but also reduces maintenance needs in humid or abrasive environments. Ideal for OEM and MRO use, this fastener delivers consistent performance in industrial fastening systems requiring durability and compliance with stringent standards.

Specification Summary & Compliance

This product adheres to precise dimensional standards with Class 3A thread fit and UNC coarse threading (1/4"-20 size), ensuring accurate engagement and interchangeability. It meets ASME B18.3 and ASTM F835 specifications for mechanical properties and manufacturing consistency. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) confirms environmental safety and regulatory adherence, supporting sustainable industrial practices.