S-91253A593 5/16"-18 x 2 1/2" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 130,000 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 harsh industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, minimizing loosening in critical machinery.
• Efficient hex drive design with a 3/16" drive size allows for easy installation and removal using standard tools, saving time on assembly lines.
• Partially threaded shank offers optimal grip and clamping force where needed, enhancing joint stability without unnecessary threading.
• High hardness rating of Rockwell C39 ensures durability and wear resistance, ideal for repetitive use in heavy-duty equipment.
• Compliance with major standards including ASME B18.3 and ASTM F835 guarantees consistency and reliability for quality-conscious procurement.

Professional Applications & Engineering Value

These 5/16"-18 UNC flat head socket cap screws are engineered to address common industrial challenges, such as vibration-induced loosening and corrosion in machinery assemblies. The Black-Oxide Alloy Steel construction provides a robust barrier against moisture and chemicals, while the Class 3A thread fit ensures precise engagement for secure fastening in high-vibration environments like automotive or aerospace systems. The partially threaded design allows for focused clamping force, reducing stress concentrations and improving load distribution. Ideal for applications requiring flush mounting, such as in enclosures or precision equipment, these screws deliver reliable performance backed by stringent manufacturing standards, supporting efficient maintenance and long-term operational safety.

Specification Summary & Compliance

This product adheres to precise dimensional tolerances, including a Class 3A thread fit for superior accuracy and UNC coarse threading with 18 threads per inch. It meets ASME B18.3 and ASTM F835 specifications for consistency in industrial use. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, it ensures environmental safety and material restrictions are upheld for global supply chain integration.