S-91255A042 5/16"-24 x 2" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional Tensile Strength – With 120,000 psi tensile strength, this screw provides reliable holding power for heavy-duty and high-stress applications, reducing the risk of fastener failure.
• Precise Class 3A Thread Fit – Ensures tight, secure connections with minimal backlash, ideal for machinery and equipment requiring high vibration resistance and accuracy.
• Durable Black-Oxide Finish – The alloy steel with black-oxide coating offers enhanced corrosion resistance, extending service life in demanding industrial environments.
• Easy Installation with Hex Drive – The 3/16" hex drive allows for quick, high-torque installation using standard tools, improving assembly efficiency and reducing labor time.
• Fully Threaded Design – Provides consistent grip along the entire 2" length, ensuring uniform clamping force and stability in assembled components.
• Fine Thread Spacing (UNF) – Delivers superior holding strength in materials prone to stripping, making it suitable for precision engineering and metal assemblies.
• High Hardness (Rockwell C39) – Resists wear and deformation under load, maintaining thread integrity and performance over repeated use cycles.

Professional Applications & Engineering Value

Engineered for demanding industrial settings, these Black-Oxide Alloy Steel Rounded Head Screws address critical fastening challenges with their robust Class 3A UNF fine threads and high tensile strength. The combination of 120,000 psi tensile rating and Rockwell C39 hardness ensures reliable performance in high-vibration machinery, automotive assemblies, and heavy equipment, where loosening or failure can lead to costly downtime. The fully threaded design and hex drive enable secure, efficient installation in tight spaces, while the rounded button head minimizes protrusion for streamlined, safe surfaces. Ideal for OEM and MRO applications, these screws provide long-term durability and compliance with industry standards, reducing maintenance needs and enhancing operational safety.

Specification Summary & Compliance

This screw features precise 5/16"-24 UNF fine threads with Class 3A fit for high accuracy and load distribution. Manufactured to meet ASME B18.3 and ASTM F835 specifications, ensuring dimensional consistency and performance reliability. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally safe and sustainable industrial practices.