S-90585A048 1/4"-28 x 3/8" 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 and extended service life.
• Exceptional mechanical strength offering 70,000 psi tensile strength and Rockwell B55 hardness for reliable performance under high stress.
• Precision flush mounting enabled by the standard 82° countersink angle and flat head design, ensuring a smooth, secure surface finish.
• High-accuracy threading with Class 3A fit and UNF fine thread for superior vibration resistance and secure fastening in critical assemblies.
• Easy and secure installation using a 5/32" hex drive, providing positive torque transfer and reducing the risk of stripping.
• Full thread engagement along the 3/8" length for maximum grip and load distribution in thin materials or deep applications.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring quality, safety, and environmental responsibility.

Professional Applications & Engineering Value

This 1/4"-28 UNF Flat Head Screw in 316 Stainless Steel is engineered to address common industrial challenges such as corrosion in marine, chemical, and outdoor settings. The passivated finish enhances its inherent resistance to oxidants, while the fine UNF thread and Class 3A fit provide excellent vibration resistance, making it ideal for precision machinery, electronic enclosures, and automotive assemblies. The flat head with 82° countersink ensures a flush fit, preventing snagging and maintaining aerodynamic or aesthetic surfaces. Its fully threaded design and hex drive facilitate quick, reliable installations in applications demanding high tensile strength and durability, reducing maintenance needs and downtime.

Specification Summary & Compliance

This screw adheres to precise dimensional tolerances, including a head diameter of 0.531" with a tolerance of -0.051" to 0", and features a Class 3A thread fit for high precision. It conforms to ASME B18.3 manufacturing specifications and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it meets stringent environmental and safety standards for industrial use.