S-91858A581 5/16"-18 x 3/4" ASME B18.6.3 Stainless Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction, ideal for harsh industrial environments and chemical exposure
• Exceptional mechanical strength offering 70,000 psi tensile strength and Rockwell B80 hardness for reliable load-bearing performance
• Precision thread fit with Class 2A UNC coarse threads ensuring smooth installation and secure fastening in various materials
• Full threading design provides maximum grip length and uniform stress distribution along the entire screw
• Standard 82° countersink angle enables flush mounting with common countersunk holes for clean, professional finishes
• Enhanced surface protection through passivated finish that improves corrosion resistance and extends service life
• Regulatory compliance assurance meeting ASME B18.6.3 specifications and environmental standards including RoHS 3 and REACH

Professional Applications & Engineering Value

This 5/16"-18 UNC flat head slotted screw in 316 stainless steel delivers critical performance advantages for demanding industrial applications. The combination of marine-grade stainless steel and passivated finish provides exceptional protection against corrosion, making it ideal for chemical processing, marine environments, and food processing equipment where moisture and corrosive agents are present. The fully threaded UNC coarse thread design ensures rapid installation and superior holding power in both soft and hard materials, while the standard 82° countersink angle allows for seamless flush mounting in precision applications. Engineering value is further enhanced by the 70,000 psi tensile strength and Rockwell B80 hardness, providing reliable performance in high-stress assemblies and vibration-prone environments where fastener integrity is critical.

Specification Summary & Compliance

This flat head slotted screw features precise Class 2A thread fit with 5/16"-18 UNC coarse threading and right-hand thread direction, manufactured to exacting dimensional standards. The fastener maintains 3/4" length with standard flat head profile measuring 0.597" diameter and 0.191" height. Compliance is verified with ASME B18.6.3 specifications for dimensional accuracy and performance requirements. Environmental and safety compliance includes RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) compliance, ensuring adherence to current regulatory standards for industrial components.