S-92949A853 5/16"-18 x 9/16" ASME B18.3, ASTM F879 Stainless Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with 18-8 stainless steel construction and passivated finish, ideal for harsh industrial environments
• Superior mechanical strength with 70,000 psi tensile strength and Rockwell B55 hardness for reliable, long-lasting fastening
• Precision thread engagement with Class 3A fit and UNC coarse threads ensuring secure installation and vibration resistance
• Easy installation and removal with 3/16" hex drive providing positive torque transmission and reduced tool slippage
• Full-threaded design offering maximum grip length and uniform stress distribution across the entire fastener
• Compliant with major industry standards including ASME B18.3, RoHS 3, and REACH for guaranteed quality and environmental safety
• Optimized head profile with rounded button design providing a finished appearance while preventing snagging

Professional Applications & Engineering Value

This 5/16"-18 UNC rounded head screw delivers critical performance advantages in demanding applications where corrosion resistance and mechanical reliability are paramount. The 18-8 stainless steel material combined with passivated finish creates a robust barrier against chemical exposure and atmospheric corrosion, significantly extending service life in manufacturing equipment, marine hardware, and food processing machinery. The coarse UNC thread profile ensures rapid assembly and superior holding power in softer materials and high-vibration environments. With full threading and Class 3A fit tolerance, engineers achieve consistent clamp load distribution and reduced risk of thread stripping, making these hex drive screws ideal for precision assemblies requiring repeated maintenance access without performance degradation.

Specification Summary & Compliance

This fastener maintains precision Class 3A thread fit with UNC coarse thread profile (5/16"-18) and full threading along the 9/16" length. Manufacturing complies with ASME B18.3 specifications where identified under ASTM F879. The product is certified RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant (as of 06/14/2023 for 235 SVHC), ensuring adherence to strict environmental and safety regulations for industrial components.