S-90279A115 4-40 x 1" ASME B18.6.3 Steel Round Head Phillips Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc plating that protects against rust and extends service life in demanding industrial environments
• High tensile strength of 60,000 psi ensures reliable fastening under stress, reducing the risk of mechanical failure
• Class 2A thread fit provides consistent, easy assembly while maintaining secure connections in coarse-thread applications
• Fully threaded design offers maximum grip and holding power along the entire 1" length for versatile mounting
• Phillips No. 1 drive enables efficient installation with standard tools, minimizing slippage and damage during tightening
• ASME B18.6.3 compliance guarantees dimensional accuracy and interchangeability, ensuring reliable performance in regulated applications
• RoHS 3 and REACH compliance meets environmental and safety standards, making them suitable for global supply chains

Professional Applications & Engineering Value

These 4-40 UNC zinc-plated steel rounded head Phillips screws are engineered to address common industrial challenges such as vibration loosening and environmental degradation. The coarse UNC thread and Class 2A fit provide quick, secure fastening in materials where fine threads might strip, while the zinc plating offers a protective barrier against moisture and chemicals. With a Rockwell B69 hardness and 60,000 psi tensile strength, they maintain integrity in high-stress assemblies like machinery, electrical enclosures, and automotive components. The rounded head design distributes clamping force evenly, reducing surface damage, and the fully threaded construction ensures consistent engagement in varied material thicknesses.

Specification Summary & Compliance

These screws feature a 4-40 UNC coarse thread with Class 2A thread fit for standard tolerance and easy assembly. Manufactured to meet ASME B18.6.3 specifications, they ensure precise dimensions including a 1" length, 0.211" head diameter, and No. 1 Phillips drive. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) confirms adherence to environmental and health regulations, supporting use in international markets.