S-91781A728 1/2"-13 x 4" ASME B18.6.3 Stainless Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance thanks to 18-8 Stainless Steel construction and passivated finish, ideal for harsh industrial environments
• Exceptional mechanical strength with 80,000 psi tensile strength and Rockwell B80 hardness for reliable, long-term load-bearing performance
• Precision thread engagement with Class 2A fit and UNC coarse threading ensures secure fastening and reduces cross-threading risks
• Optimized flush mounting with standard 82° countersink angle and flat head design for smooth, unobtrusive surface finishes
• Enhanced installation control through slotted drive style, providing straightforward tool compatibility and torque application
• Regulatory peace of mind with full compliance to ASME B18.6.3, RoHS 3, and REACH standards for quality and environmental safety
• Versatile partial threading design allows for effective clamping force on specific unthreaded shaft sections

Professional Applications & Engineering Value

These 1/2"-13 UNC Flat Head Screws deliver critical engineering solutions where corrosion resistance and structural integrity are paramount. Manufactured from 18-8 Stainless Steel with a passivated finish, they effectively combat oxidation and chemical exposure in demanding settings like marine equipment, food processing machinery, and outdoor structural assemblies. The partially threaded configuration combined with coarse UNC threads provides superior grip in softer materials and allows precise adjustment of clamping zones. With an 82° countersink angle and flat head profile, they ensure seamless surface integration, eliminating protrusions that could snag or collect debris. This makes them ideal for industrial applications requiring both aesthetic cleanliness and mechanical reliability under vibration and stress.

Specification Summary & Compliance

This 4" length flat head screw features a 1/2"-13 UNC thread with Class 2A dimensional accuracy for consistent fit. Manufacturing adheres to ASME B18.6.3 specifications, ensuring dimensional and mechanical reliability. The product is confirmed RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting stringent environmental and safety regulations for industrial components.