S-90291A540 1/4"-20 ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ensuring long-term reliability in harsh environments.
• Precise Class 3A thread fit for tight, secure fastening and reduced risk of loosening under vibration.
• Non-marring green nylon 6/6 plastic tip protects sensitive surfaces from damage while maintaining strong grip.
• Wide temperature tolerance from -50° to 250°F, allowing consistent performance in varied operating conditions.
• High hardness rating (Rockwell B80) provides excellent wear resistance and durability under load.
• 1/8" hex drive design enables easy installation and removal with standard tools in confined spaces.
• Compliance with ASME B18.3, RoHS, and REACH ensures adherence to industry standards and environmental regulations.

Professional Applications & Engineering Value

This 1/4"-20 UNC hex headless set screw is engineered to address critical challenges in industrial assembly, such as component slippage and surface damage. The 18-8 stainless steel material offers excellent corrosion resistance, making it ideal for applications in machinery, automotive, and electronics where exposure to moisture or chemicals is common. The Class 3A thread fit and coarse thread spacing provide a secure, vibration-resistant hold, while the green nylon tip prevents marring on finished surfaces—essential for precision equipment and consumer products. Its right-hand thread direction and 1/8" hex drive simplify installation in tight spaces, reducing assembly time and improving efficiency. By combining durability with protective features, this set screw ensures reliable performance in demanding industrial applications, from securing shafts to aligning components.

Specification Summary & Compliance

This set screw features a 1/4"-20 UNC thread with Class 3A fit for high precision and a coarse thread spacing to enhance grip. It complies with ASME B18.3 manufacturing standards and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safety and sustainability. The dimensions include a 0.25" thread diameter and 3/4" length, with a Rockwell B80 hardness for consistent mechanical performance.