S-90275A578 5/16"-18 x 1/2" ASME B18.6.3 Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction for long-lasting performance in demanding environments.
• High tensile strength of 60,000 psi ensures reliable load-bearing capacity and prevents failure under stress.
• Class 2A thread fit provides consistent, easy assembly and interchangeability with standard nuts and tapped holes.
• 82° countersink angle and undercut flat head allow for a flush, secure fit that minimizes protrusion and snagging risks.
• Fully threaded design offers maximum grip and holding power along the entire screw length.
• Rockwell B70 hardness enhances durability and resistance to wear and deformation during installation and use.
• Compliance with ASME B18.6.3, RoHS 3, and REACH guarantees quality, safety, and environmental standards are met for industrial applications.

Professional Applications & Engineering Value

This 5/16"-18 UNC flat head screw is engineered to address critical assembly challenges in industrial settings. The zinc-plated steel material provides excellent corrosion protection, extending service life in humid or outdoor conditions. Its fully threaded coarse (UNC) design ensures rapid installation and superior pull-out resistance, making it ideal for metal fabrication, machinery, and structural frameworks. The 82° countersink angle and undercut flat head profile enable a seamless, low-profile finish that reduces aerodynamic drag and improves safety in moving parts. With a slotted drive for straightforward manual or automated driving, this screw streamlines production while maintaining high tensile strength and hardness to withstand vibration and dynamic loads.

Specification Summary & Compliance

This fastener adheres to precise dimensional standards, including Class 2A thread fit for consistent tolerance and UNC coarse threading (5/16"-18) for robust engagement. It meets ASME B18.6.3 specifications for dimensional accuracy and performance. Environmental and safety compliance is assured through RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) adherence, confirming the absence of hazardous substances. The screw is fully threaded with a length of 1/2" and a right-hand thread direction, designed for reliable use in various industrial assemblies.