S-90585A587 5/16"-18 x 1 1/2" 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
• Exceptional mechanical strength offering 70,000 psi tensile strength and Rockwell B55 hardness for reliable performance under high stress
• Precise, secure fastening ensured by Class 3A thread fit and UNC coarse threads, reducing the risk of cross-threading and loosening
• Efficient installation and removal with a 3/16" hex drive, providing a positive grip and minimizing tool slippage
• Flush surface finish due to the standard 82° countersink angle and flat head design, preventing snagging and improving aesthetics
• Full threading along the 1 1/2" length for maximum grip and holding power in a wide range of material thicknesses
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring safety, quality, and environmental responsibility

Professional Applications & Engineering Value

These 316 stainless steel flat head screws are engineered to solve critical challenges in demanding industrial settings. The passivated finish significantly enhances corrosion resistance, making them ideal for marine, chemical processing, and outdoor applications where exposure to moisture and corrosive agents is a constant concern. The combination of 70,000 psi tensile strength and a Class 3A UNC thread fit ensures a secure, vibration-resistant connection in heavy machinery, structural assemblies, and high-stress equipment. The flat head with an 82° countersink allows for a clean, flush installation, which is crucial for applications involving moving parts or where a smooth surface is required for safety and operational efficiency. This makes them a reliable heavy-duty fastener for engineers and procurement specialists seeking durability and compliance.

Specification Summary & Compliance

This product adheres to precise dimensional standards, including a Class 3A thread fit for superior accuracy and a coarse UNC 5/16"-18 thread. Manufacturing and quality are governed by the ASME B18.3 specification. The screw is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free of hazardous substances and meets strict environmental and safety standards for industrial use.