S-90291A857 1/4"-28 ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Non-marring protection with Nylon 6/6 plastic tip to prevent damage to shafts and components during secure fastening.
• Exceptional corrosion resistance from 18-8 stainless steel construction, ideal for harsh or washdown environments.
• Superior vibration resistance and holding power with fine UNF threads and Class 3A fit for precision assemblies.
• Broad temperature tolerance (-50° to 250°F) ensures reliable performance in both extreme cold and moderate heat.
• Easy installation and removal using a standard 1/8" hex key in confined, headless designs.
• High mechanical strength with Rockwell B80 hardness for durable, long-term use without stripping or deformation.
• Regulatory compliance with ASME B18.3, RoHS 3, and REACH for safe, industry-approved applications.

Professional Applications & Engineering Value

This 1/4"-28 UNF Class 3A nylon tip set screw is engineered to solve critical industrial challenges, such as component slippage and surface damage in precision machinery. The 18-8 stainless steel body offers excellent corrosion resistance, while the Nylon 6/6 plastic tip provides a soft, non-abrasive contact point—ideal for securing gears, pulleys, and collars without marring finished surfaces. Its fine thread and Class 3A fit ensure tight, vibration-resistant fastening in high-stress assemblies, from automotive systems to electronic enclosures. With a wide operating temperature range and hex headless design, it delivers reliable performance in space-constrained, demanding environments, reducing maintenance and replacement costs.

Specification Summary & Compliance

This set screw features a 1/4"-28 UNF fine thread with Class 3A thread fit for precise, tight-tolerance assemblies. It is manufactured in compliance with ASME B18.3 standards and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safety and sustainability in industrial use.