S-92210A337 1/4"-28 x 1 1/4" ASME B18.3 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 Stainless Steel and passivated finish for long-term reliability in harsh environments.
• Exceptional mechanical strength offering 70,000 psi tensile strength and Rockwell B55 hardness to withstand high-stress applications.
• Precise thread engagement with Class 3A fit and fine UNF threading for secure, vibration-resistant fastening.
• Efficient installation and flush finish thanks to the standard flat head with 82° countersink angle and 5/32" hex drive.
• Full thread coverage along the 1 1/4" length ensures maximum grip and load distribution.
• Compliance with industry standards including ASME B18.3 for consistent quality and performance.
• Environmentally responsible manufacturing with RoHS 3 and REACH compliance for safe use in regulated industries.

Professional Applications & Engineering Value

These 1/4"-28 UNF flat head screws are engineered to address common industrial challenges such as component loosening under vibration and corrosion in demanding settings. The 18-8 Stainless Steel material, combined with a passivated finish, provides excellent resistance to oxidation and chemical exposure, making them ideal for machinery, automotive assemblies, and outdoor equipment. The Class 3A thread fit and fine thread spacing ensure tight tolerances, reducing the risk of backlash and improving joint integrity. With a hex drive and flat head design, they allow for quick, tool-friendly installation and a smooth surface finish, minimizing protrusion in precision applications. This combination of durability, precision, and ease of use delivers reliable performance in industrial screws for critical fastening needs.

Specification Summary & Compliance

This product features precise Class 3A thread fit per UNF standards, with a thread size of 1/4"-28 and fine spacing for accurate engagement. Dimensions include a head diameter of 0.531", length of 1 1/4", and an 82° countersink angle. It complies with ASME B18.3 specifications for consistent manufacturing quality. Additionally, it meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and suitability for global industrial markets.