S-91255A044 3/8"-24 x 5/8" 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.
• Superior corrosion resistance from the black-oxide finish on alloy steel, extending service life in demanding industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies in critical applications.
• Hex drive design (7/32") allows for high-torque installation with standard tools, minimizing slippage and improving efficiency.
• Fully threaded UNF fine thread offers enhanced grip and load distribution, ideal for fine-adjustment and high-clamp force needs.
• Rounded button head profile reduces snagging and provides a low-profile, aesthetically clean finish for assembled products.
• Compliance with ASME, ASTM, RoHS, and REACH ensures adherence to industry standards and environmental regulations for global supply chain compatibility.

Professional Applications & Engineering Value

This black-oxide alloy steel rounded head hex screw is engineered to address common industrial challenges such as vibration loosening, corrosion, and high mechanical stress. The Class 3A UNF fine thread ensures precise fitment, reducing the likelihood of cross-threading and providing superior holding power in machinery, automotive, and aerospace assemblies. The hex drive facilitates efficient installation with standard wrenches, enhancing productivity in high-volume manufacturing. Its high tensile strength and Rockwell C39 hardness make it suitable for heavy-duty applications where durability and reliability are paramount, while the black-oxide surface treatment offers added protection against rust and wear in harsh operating conditions.

Specification Summary & Compliance

This screw features a 3/8"-24 UNF fine thread with Class 3A fit, ensuring high precision and interchangeability. It is manufactured in accordance with ASME B18.3 and ASTM F835 specifications, guaranteeing consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible sourcing and use in regulated industries.