S-90279A107 4-40 x 5/16" ASME B18.6.3 Steel Round Head Phillips Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, ideal for harsh industrial environments
• High tensile strength of 60,000 psi ensures reliable fastening under demanding mechanical loads
• Rockwell B69 hardness provides excellent durability and resistance to wear and deformation
• Class 2A thread fit with UNC coarse threading offers quick assembly and secure holding power
• Fully threaded design maximizes grip and load distribution across the entire length
• Phillips drive (No. 1 size) allows for efficient installation with standard tools, reducing assembly time
• Compliance with ASME B18.6.3, RoHS 3, and REACH ensures quality, safety, and environmental standards are met

Professional Applications & Engineering Value

These 4-40 UNC zinc-plated steel rounded head Phillips screws are engineered to address common industrial challenges, such as corrosion and mechanical stress. The zinc-plated steel material provides a protective barrier against rust and oxidation, extending service life in applications like machinery assembly, electronics enclosures, and automotive components. The coarse UNC threads and Class 2A fit ensure easy alignment and strong retention, reducing the risk of loosening under vibration. With a rounded head profile and Phillips drive, they offer a flush finish and straightforward installation, minimizing labor costs and enhancing reliability in high-volume production environments.

Specification Summary & Compliance

This product adheres to precise dimensional standards, including a Class 2A thread fit and UNC coarse threading for consistent performance. It meets ASME B18.6.3 specifications for quality and interchangeability, and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material restrictions are upheld.