S-98164A211 1/4"-20 x 1/2" ASME B18.3, ASTM F879 Stainless Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance from 316 stainless steel and passivated finish, ideal for harsh environments like marine or chemical processing
• High-strength performance with 70,000 psi tensile strength and Rockwell B55 hardness for reliable, heavy-duty fastening
• Precise, secure threading with Class 3A fit and UNC coarse thread, ensuring vibration resistance and easy assembly
• Efficient installation and removal via 5/32" hex drive, providing excellent torque transfer and reduced tool slippage
• Consistent dimensional accuracy per ASME B18.3 standards, guaranteeing interchangeability and fit in OEM applications
• Full regulatory compliance with RoHS 3 and REACH, making it safe for use in regulated industries worldwide
• Versatile fully threaded design allows for adjustable grip length and uniform load distribution along the entire shank

Professional Applications & Engineering Value

This 316 stainless steel rounded head screw is engineered to address critical challenges in demanding industrial settings, where exposure to moisture, chemicals, and stress can compromise fastener integrity. The combination of 316 stainless steel material and a passivated finish significantly enhances pitting and crevice corrosion resistance, extending service life in applications like marine equipment, food processing machinery, and pharmaceutical installations. The UNC coarse thread and Class 3A thread fit provide superior holding power and ease of alignment, reducing the risk of cross-threading during high-volume assembly. With a hex drive and rounded button head, it offers a low-profile, snag-resistant design that is both user-friendly and suitable for spaces with clearance constraints. These features make it an optimal choice for engineers seeking durable, compliant fasteners that maintain performance under continuous mechanical load and corrosive conditions.

Specification Summary & Compliance

This screw adheres to Class 3A thread fit tolerances and UNC coarse thread specifications, ensuring precise engagement and reliability. It is manufactured in compliance with ASME B18.3 standards for dimensional consistency and mechanical properties. The product fully meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulatory requirements, confirming its safety and environmental compliance for global industrial use.