S-91500A913 1/4"-20 x 1" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 Stainless Steel construction and passivated finish, ideal for harsh industrial and marine environments.
• Exceptional mechanical strength offering 70,000 psi tensile strength and Rockwell B80 hardness for reliable, long-term fastening under high stress.
• Optimized flush mounting with an undercut flat head and 82° countersink angle, ensuring a secure, non-protruding fit in precision applications.
• Efficient installation and removal facilitated by the Phillips No. 3 drive, reducing cam-out risks and speeding up assembly processes.
• Reliable thread engagement with a fully threaded 1/4"-20 UNC coarse thread and Class 2A fit, providing consistent clamping force and vibration resistance.
• Broad compliance assurance meeting ASME B18.6.3 standards, RoHS 3, and REACH regulations, ensuring quality and environmental safety for global supply chains.

Professional Applications & Engineering Value

This 1/4"-20 UNC flat head screw is engineered to address critical challenges in demanding sectors like marine, chemical processing, and outdoor infrastructure. Its 316 Stainless Steel material, enhanced by a passivated finish, provides exceptional resistance to chlorides, acids, and moisture, preventing premature failure in corrosive settings. The undercut flat head profile and 82° countersink angle allow for a flush, secure fit that minimizes surface protrusion and distributes stress effectively, reducing the risk of material cracking. Combined with a coarse UNC thread and full threading, it ensures rapid installation and robust holding power in wood, metal, and composite assemblies, making it a reliable choice for applications where vibration resistance and long-term durability are paramount.

Specification Summary & Compliance

This screw adheres to precise dimensional standards, including a Class 2A thread fit for consistent assembly tolerance and a 1/4"-20 UNC coarse thread profile. Manufactured in compliance with ASME B18.6.3 specifications, it ensures reliable performance in mechanical fastening. The product is also verified as RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, confirming its adherence to strict environmental and safety regulations for hazardous substance restrictions.