S-90291A533 1/4"-20 ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Secure Fastening with Minimal Damage: The nylon 6/6 plastic tip provides excellent resistance to vibration loosening while protecting mating surfaces from scratches and galling, ensuring a reliable, non-marring hold.
• Superior Corrosion Resistance: Constructed from 18-8 Stainless Steel, this set screw offers excellent durability and resistance to rust and corrosion in various industrial environments.
• Precise, High-Strength Threading: The UNC Class 3A coarse thread ensures a tighter fit and higher fastening strength compared to Class 2A, providing superior resistance to stripping and vibration.
• Optimized for High-Torque Applications: The 1/8" hex drive in a headless design allows for high torque application in confined spaces and prevents snagging, making installation and removal efficient.
• Stable Performance Across Temperatures: The nylon tip maintains its integrity and locking ability across a wide temperature range from -50° to 250° F, ensuring consistent performance.
• Enhanced Durability and Wear Resistance: With a Rockwell B80 hardness, the screw offers a robust balance of strength and ductility, resisting deformation under load.
• Quick Visual Identification: The distinctive green tip allows for easy and quick identification during assembly and quality checks, streamlining inventory and installation processes.

Professional Applications & Engineering Value

This 1/4"-20 UNC Class 3A hex headless set screw is engineered to solve critical challenges in precision assembly and machinery. The 18-8 Stainless Steel construction provides essential corrosion resistance for harsh environments, while the coarse UNC thread ensures rapid installation and a secure, high-strength fit in components like pulleys, gears, and collars. The nylon 6/6 tip is a key feature, acting as a self-locking element that dampens vibrations and prevents backlash without damaging the shaft or hub surface. This makes it ideal for applications requiring repeated adjustments and disassembly, such as in automotive, aerospace, and conveyor systems, where vibration resistance and component protection are paramount. Its headless design with a 1/8" hex drive is perfect for space-constrained assemblies, offering a flush finish and high torque capability.

Specification Summary & Compliance

This set screw adheres to strict dimensional and performance standards, including a 1/4"-20 UNC Class 3A thread for precise fit and high strength. It is manufactured in compliance with ASME B18.3 specifications, ensuring interchangeability and reliability. The product is also RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, confirming it is free of hazardous substances and safe for use in regulated markets.