S-91773A128 5-40 x 1/2" ASME B18.6.3 Stainless Steel Round Head Phillips Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel and passivated finish, ideal for harsh environments and long-term reliability.
• High tensile strength of 100,000 psi ensures secure, durable fastening under significant mechanical stress.
• Rockwell B100 hardness provides excellent wear resistance and maintains thread integrity over repeated use.
• Class 2A thread fit and UNC coarse threading offer easy, quick assembly and reliable engagement in a variety of materials.
• Fully threaded design maximizes grip length and holding power across the entire screw length.
• Phillips drive (No. 2 size) allows for efficient installation with common tools, reducing assembly time.
• Compliance with ASME B18.6.3, RoHS 3, and REACH ensures quality, safety, and environmental standards are met for global industrial use.

Professional Applications & Engineering Value

These 5-40 UNC rounded head screws are engineered to address common industrial challenges, such as corrosion and mechanical failure in demanding applications. Made from 18-8 stainless steel with a passivated finish, they provide exceptional resistance to rust and chemicals, making them ideal for use in marine, chemical processing, and outdoor equipment. The coarse UNC threads and Class 2A fit ensure quick, reliable fastening in metals and plastics, reducing installation errors and improving productivity. With a rounded head and Phillips drive, they offer a low-profile, user-friendly solution for assemblies requiring flush mounting and easy access. This combination of high tensile strength and full threading delivers consistent performance in machinery, electronics, and automotive components, where vibration resistance and long-term durability are critical.

Specification Summary & Compliance

This product adheres to precise dimensional standards, including Class 2A thread fit and UNC coarse threading with a thread size of 5-40 and length of 1/2 inch. It meets ASME B18.6.3 specifications for mechanical and dimensional requirements, ensuring interoperability and reliability. Additionally, it is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), confirming it is free from hazardous substances and suitable for environmentally conscious industrial applications.