S-90600A133 5/16"-18 x 1/2" ASME B18.3 Stainless Steel Button Head Torx Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 Stainless Steel construction and passivated finish, ideal for harsh industrial environments
• Enhanced torque transmission through T40 Torx drive design, reducing cam-out and tool slippage during installation
• Precise thread engagement with Class 3A thread fit and UNC coarse threading, ensuring reliable fastening in demanding applications
• High mechanical strength with 60,000 psi tensile strength and Rockwell B55 hardness, providing excellent load-bearing capacity
• Optimized head design featuring a rounded button profile that sits flush while distributing clamping force evenly
• Full threading coverage along the 1/2" length for maximum grip and consistent holding power across the entire fastener
• Regulatory compliance assurance meeting ASME B18.3 standards and environmental regulations including RoHS 3 and REACH

Professional Applications & Engineering Value

These 18-8 Stainless Steel rounded head screws deliver exceptional performance in critical industrial fastening applications where corrosion resistance and mechanical reliability are paramount. The combination of passivated finish and stainless steel material provides superior protection against chemical exposure and environmental degradation, significantly extending service life in manufacturing equipment, machinery assemblies, and outdoor installations. The T40 Torx drive system enables higher torque application without stripping, while the Class 3A thread fit with UNC coarse threading ensures rapid installation and secure fastening in vibration-prone environments. The rounded button head design offers a low-profile solution that minimizes protrusion while maintaining excellent clamping force distribution.

Specification Summary & Compliance

This 5/16"-18 x 1/2" fully threaded screw features precise Class 3A thread fit with UNC coarse thread specifications (18 TPI) and right-hand threading orientation. Manufactured to ASME B18.3 standards with dimensional accuracy including 0.547" head diameter and 0.166" head height. The fastener demonstrates full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, containing no restricted substances per the latest compliance verification. Mechanical properties include 60,000 psi tensile strength and Rockwell B55 hardness for consistent performance across industrial applications.