S-91781A587 5/16"-18 x 1 1/2" ASME B18.6.3 Stainless Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 Stainless Steel and passivated finish, ideal for harsh environments and long-term reliability.
• High tensile strength of 80,000 psi ensures secure, durable fastening under heavy loads and vibration.
• Rockwell B80 hardness provides excellent wear resistance and maintains thread integrity during installation and use.
• Fully threaded design offers maximum grip and holding power along the entire screw length for versatile applications.
• Standard 82° countersink angle allows for a flush, clean finish in countersunk holes, reducing snagging and improving safety.
• Class 2A thread fit with UNC coarse threading enables quick, easy assembly and reliable performance in a wide range of materials.
• Compliance with ASME B18.6.3, RoHS 3, and REACH ensures adherence to industry standards and environmental regulations for safe, responsible sourcing.

Professional Applications & Engineering Value

These 18-8 Stainless Steel flat head screws are engineered to address common industrial challenges such as corrosion, mechanical stress, and assembly efficiency. The passivated finish enhances the natural corrosion resistance of stainless steel, making these slotted screws suitable for outdoor, marine, and chemical-exposed environments where rust prevention is critical. The fully threaded UNC coarse design ensures rapid installation and strong holding power in wood, metal, and plastic assemblies, reducing labor time and minimizing loosening from vibrations. With an 82° countersink angle, they sit flush in components, eliminating protrusions that could interfere with machinery operation or safety. Ideal for construction, automotive, and electrical enclosures, these screws deliver consistent performance while meeting ASME B18.6.3 specifications for dimensional accuracy and reliability.

Specification Summary & Compliance

This product adheres to Class 2A thread fit per UNC standards, ensuring precise dimensional tolerances for reliable engagement. Manufacturing complies with ASME B18.6.3 for consistent quality and performance. Environmental and safety standards include full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), confirming the absence of restricted hazardous substances for sustainable industrial use.