S-91099A483 5/16"-18 x 1" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with passivated 18-8 stainless steel construction, ensuring long-term reliability in harsh environments
• Exceptional mechanical strength with 80,000 psi tensile strength and Rockwell B80 hardness for demanding applications
• Precision thread engagement through Class 2A fit and UNC coarse threads, providing secure fastening and vibration resistance
• Optimized flush mounting with 82° countersink angle and undercut flat head design for seamless surface finishing
• Enhanced installation efficiency with Phillips No. 4 drive, enabling quick assembly while minimizing cam-out risks
• Full-threaded reliability along the entire 1" length, ensuring maximum grip and load distribution
• Regulatory compliance assurance meeting ASME B18.6.3 specifications and environmental standards (RoHS 3, REACH)

Professional Applications & Engineering Value

Engineered for industrial applications requiring flush surface mounting and corrosion-resistant performance, these 5/16"-18 UNC flat head screws solve critical challenges in machinery assembly, electronic enclosures, and structural frameworks. The passivated 18-8 stainless steel construction prevents galvanic corrosion and withstands chemical exposure, while the undercut flat head profile ensures proper seating without material protrusion. The coarse UNC thread design provides superior holding power in softer materials and reduces cross-threading incidents during high-volume assembly operations. With 80,000 psi tensile strength, these industrial fasteners maintain structural integrity under dynamic loads and thermal cycling, making them ideal for automotive, marine, and manufacturing applications where reliability is paramount.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 2A thread fit and UNC coarse thread spacing (5/16"-18), ensuring consistent performance across applications. Complies with ASME B18.6.3 mechanical and dimensional specifications, featuring 82° countersink angle and fully threaded design. Meets environmental regulations including RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) standards for hazardous substance restrictions.