S-90585A049 1/4"-28 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 and passivated finish, ideal for harsh environments like marine or chemical processing.
• High tensile strength of 70,000 psi ensures reliable, long-lasting fastening under heavy loads and vibration.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies in critical applications.
• Fully threaded 1/4"-28 UNF design with fine spacing offers excellent grip and load distribution across the entire length.
• 82° countersink angle and flat head allows for a flush, clean finish, reducing snagging and improving aesthetics.
• Hex drive (5/32") enables easy installation and high torque application without stripping, speeding up assembly.
• Compliance with ASME B18.3, RoHS 3, and REACH guarantees quality, safety, and environmental standards for global industrial use.

Professional Applications & Engineering Value

This 316 stainless steel flat head screw is engineered to address common industrial challenges such as corrosion, high stress, and precise fit requirements. The passivated finish enhances its resistance to oxidization and chemicals, making it suitable for applications in marine equipment, food processing machinery, and pharmaceutical devices where hygiene and durability are critical. The Class 3A thread fit and UNF fine threading ensure minimal backlash and superior holding power in dynamic environments, reducing maintenance needs. With a tensile strength of 70,000 psi and Rockwell B55 hardness, it provides reliable performance in assemblies subject to vibration and thermal cycling, offering engineers a robust fastening solution that maintains integrity over time.

Specification Summary & Compliance

This screw features precise dimensions including a 1/4"-28 UNF thread size with Class 3A thread fit for high accuracy, a length of 1 1/4", and standard 82° countersink angle. It meets ASME B18.3 specifications for consistency and performance, and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from hazardous substances and safe for various industrial and export markets.