S-90585A728 1/2"-13 x 4" ASME B18.3 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction and passivated finish, ideal for harsh environments and extended service life
• High-strength performance with 70,000 psi tensile strength and Rockwell B55 hardness, ensuring reliable load-bearing capacity
• Precise thread engagement with Class 3A thread fit for secure, vibration-resistant assemblies in critical applications
• Efficient installation featuring a standard 82° countersink angle and 5/16" hex drive for flush mounting and easy torque application
• Full threading along the 4" length provides maximum grip and adjustment flexibility in deep or variable material thicknesses
• Regulatory compliance assurance meeting ASME B18.3 specifications and RoHS/REACH environmental standards for global project suitability
• Dimensional consistency with controlled head diameter and UNC coarse threads for reliable, repeatable fastening operations

Professional Applications & Engineering Value

Engineered for demanding industrial settings, these 316 stainless steel flat head screws deliver exceptional durability where corrosion from chemicals, moisture, or salt exposure is a concern. The passivated finish enhances surface stability, reducing pitting and galling during installation. With a Class 3A thread fit and UNC coarse threads, they maintain clamping force under vibration, making them ideal for heavy machinery, marine equipment, and structural assemblies. The 82° countersink angle and hex drive design allow for streamlined, flush installations in metal fabrication, piping systems, and outdoor infrastructure, minimizing protrusion and improving safety. These screws address common failure points by combining high tensile strength with full-thread engagement, ensuring long-term performance in critical industrial fastening applications.

Specification Summary & Compliance

This flat head screw adheres to ASME B18.3 dimensional standards, with a Class 3A thread fit for precise tolerance and a UNC 1/2"-13 thread size. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety. The screw features a passivated finish on 316 stainless steel, with a head diameter of 0.938" and a length of 4", providing consistent performance across industrial applications.