S-91255A567 1/4"-28 x 1 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.
• Superior corrosion resistance from the black-oxide finish on alloy steel, extending service life and maintaining integrity in various industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, minimizing loosening and improving long-term stability.
• Convenient hex drive design with a 5/32" size allows for easy installation and removal using standard tools, boosting assembly efficiency and reducing labor time.
• Fully threaded fine UNF configuration offers enhanced grip and load distribution, ideal for applications requiring fine adjustments and secure fastening in thinner materials.
• High hardness rating of Rockwell C39 ensures durability and resistance to wear, supporting repeated use without degradation in performance.
• Compliance with major standards including ASME B18.3 and ASTM F835, guaranteeing consistency and reliability for quality-conscious industrial projects.

Professional Applications & Engineering Value

This 1/4"-28 UNF rounded head screw is engineered to address common industrial challenges such as vibration-induced loosening and material fatigue. Crafted from black-oxide alloy steel, it combines high tensile strength with excellent corrosion resistance, making it suitable for machinery, automotive assemblies, and precision equipment where reliability is critical. The fine thread and Class 3A fit ensure a secure, tight hold in applications requiring minimal play, while the hex drive facilitates quick installation in confined spaces. Ideal for OEM and MRO uses, this screw helps reduce maintenance intervals and enhances overall system durability, delivering long-term value in demanding environments.

Specification Summary & Compliance

This product adheres to precise dimensional standards, including a Class 3A thread fit for superior accuracy and a UNF fine thread with 1/4"-28 size. It meets ASME B18.3 and ASTM F835 specifications, ensuring consistent manufacturing quality. Additionally, it is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmental and safety standards in global supply chains.