S-90585A585 5/16"-18 x 1 1/4" ASME B18.3 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction, ideal for harsh chemical and marine environments
• Enhanced durability and strength with 70,000 psi tensile strength and Rockwell B55 hardness for heavy-duty applications
• Precise thread engagement through Class 3A thread fit and UNC coarse threading, ensuring reliable fastening in demanding conditions
• Secure flush mounting with standard 82° countersink angle and flat head design, minimizing protrusion in assembled components
• Easy installation and removal using 3/16" hex drive, providing efficient torque application without slippage
• Long-term performance protection with passivated finish, increasing surface durability and corrosion resistance
• Full regulatory compliance meeting ASME B18.3 standards, RoHS 3, and REACH requirements for global industrial use

Professional Applications & Engineering Value

These 316 stainless steel flat head screws deliver exceptional value in corrosive environments where fastener failure is not an option. The combination of fully threaded UNC coarse spacing and Class 3A thread fit ensures maximum engagement strength in soft materials and vibration-prone applications. The passivated finish enhances the natural corrosion resistance of 316 stainless steel, making these hex drive screws ideal for chemical processing equipment, marine hardware, and food processing machinery where exposure to chlorides and acidic conditions is common. The 82° countersink angle provides reliable flush seating in standard countersunk holes, while the 1 1/4" length offers versatile fastening depth for various material thicknesses in industrial assembly operations.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 3A thread fit tolerance and UNC thread form per ASME B18.3 specifications. These flat head screws feature a head diameter of 0.656" with tolerance range of -0.056" to 0" and standard 82° countersink profile. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental responsibility and workplace safety. The mechanical properties include 70,000 psi tensile strength and Rockwell B55 hardness, providing reliable performance in demanding industrial applications.