S-93791A589 1/4"-20 x 2 1/2" ASME B18.3 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and black-oxide passivated finish, ideal for harsh industrial environments.
• Exceptional mechanical strength offering 70,000 psi tensile strength and Rockwell B55 hardness for reliable, heavy-duty fastening.
• Precise thread engagement with UNC coarse threading and Class 3A fit, ensuring secure connections and reduced cross-threading risk.
• Efficient installation and flush finish thanks to the standard 82° countersink angle and 5/32" hex drive for easy torque application.
• Full-length threading provides consistent holding power along the entire 2-1/2" length for versatile applications.
• Compliance with major standards including ASME B18.3, RoHS 3, and REACH, guaranteeing quality and environmental safety.
• Durable and long-lasting performance due to the material and finish combination, reducing maintenance needs and replacement costs.

Professional Applications & Engineering Value

This 1/4"-20 flat head screw is engineered to address critical challenges in industrial and mechanical assemblies where corrosion resistance, high strength, and reliable fastening are paramount. The 18-8 stainless steel material, enhanced by a black-oxide passivated finish, provides excellent protection against rust and chemical exposure, making it suitable for outdoor equipment, marine applications, and manufacturing machinery. The UNC coarse thread and Class 3A fit ensure quick, secure installation with minimal risk of stripping, while the flat head design with an 82° countersink angle allows for a smooth, flush surface in countersunk holes. This screw is ideal for use in construction, automotive, and aerospace sectors, where high tensile strength and compliance with ASME B18.3 standards are essential for safety and durability. Its fully threaded design maximizes grip in various materials, offering engineers a versatile and dependable solution for demanding environments.

Specification Summary & Compliance

This screw features precise UNC coarse threading with a Class 3A fit for tight tolerances and reliable performance. It adheres to ASME B18.3 manufacturing specifications and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and quality assurance in industrial applications.