S-91500A348 5/16"-18 x 7/8" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance in harsh environments thanks to 316 stainless steel construction with a protective passivated finish.
• Exceptional mechanical strength with a 70,000 psi tensile strength and Rockwell B80 hardness for reliable, long-lasting fastening.
• Efficient installation and removal with the standard Phillips drive (No. 4 size) and coarse UNC threading for quick assembly.
• Precise and flush mounting enabled by the flat head with an 82° countersink angle, creating a smooth surface finish.
• Guaranteed dimensional accuracy and interchangeability with a Class 2A thread fit, ensuring consistent performance.
• Full-length threading provides maximum grip and holding power along the entire 7/8" length of the screw.
• Compliance with major industry standards including ASME B18.6.3, RoHS 3, and REACH for safe and regulated use.

Professional Applications & Engineering Value

This 5/16"-18 UNC flat head screw is engineered to solve critical challenges in demanding industrial applications. Manufactured from 316 stainless steel and featuring a passivated finish, it delivers outstanding resistance to corrosion, making it ideal for use in marine, chemical processing, and food-grade environments where moisture and corrosive agents are present. The fully threaded design with coarse spacing ensures a strong, secure hold in a variety of materials, while the flat head profile with its 82° countersink allows for a clean, flush installation that prevents snagging and maintains aerodynamic or aesthetic surfaces. This combination of high-strength material and precise engineering provides a reliable, durable fastening solution that reduces maintenance needs and extends the service life of your assemblies.

Specification Summary & Compliance

This screw adheres to precise dimensional standards with a Class 2A thread fit and UNC coarse thread specification. It is manufactured in compliance with the ASME B18.6.3 standard, ensuring consistent quality and performance. Furthermore, this product is confirmed to be RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting stringent environmental and safety regulations for hazardous substances.