S-90275A559 1/4"-28 x 3/4" ASME B18.6.3 Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, ensuring long-lasting performance in demanding industrial environments.
• Excellent flush-mounting capability thanks to the standard flat head profile and 82° countersink angle, providing a smooth, secure finish.
• High tensile strength of 60,000 psi and Rockwell B70 hardness for reliable load-bearing and resistance to deformation under stress.
• Precise Class 2A fine thread fit ensures easy assembly, secure fastening, and reduced risk of cross-threading in critical applications.
• Fully threaded right-hand design offers maximum grip and holding power across the entire 3/4" length for consistent performance.
• Broad compliance with ASME B18.6.3, RoHS 3, and REACH guarantees quality, safety, and environmental standards are met for global industrial use.
• Simple and reliable installation with a slotted drive style, compatible with standard tools for efficient maintenance and assembly.

Professional Applications & Engineering Value

This 1/4"-28 UNF flat head slotted screw is engineered to address common industrial challenges, such as the need for durable, corrosion-resistant fasteners in machinery, automotive, and electrical enclosures. The zinc-plated steel material provides a protective barrier against rust and wear, extending service life in harsh conditions. Its fine UNF thread and Class 2A fit ensure tight, vibration-resistant connections, reducing loosening in high-stress applications. The 82° countersink angle allows for seamless flush mounting, minimizing protrusions and enhancing safety in assembled products. Ideal for precision assemblies, this screw supports efficient production while meeting rigorous ASME B18.6.3 standards for consistent performance and reliability.

Specification Summary & Compliance

This screw features precise Class 2A thread fit per UNF standards, with a fine thread spacing for accurate engagement. Dimensions include a 1/4"-28 thread size, 3/4" length, and full threading for uniform strength. It complies with ASME B18.6.3 manufacturing specifications, ensuring dimensional accuracy and performance. Additionally, it is RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliant, confirming adherence to environmental and safety regulations for industrial use.