S-90291A581 5/16"-18 ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh industrial environments.
• Precise Class 3A thread fit ensures tight, reliable fastening with minimal backlash in demanding applications.
• Non-marring Nylon 6/6 tip protects mating surfaces from damage while maintaining a secure grip.
• Wide temperature tolerance from -50° to 250°F, ensuring consistent performance under varying thermal conditions.
• High hardness (Rockwell B80) provides excellent wear resistance and long-term durability.
• Hex drive design allows for easy installation and removal with standard tools, even in confined spaces.
• Compliance with ASME B18.3, RoHS 3, and REACH guarantees adherence to strict industrial and environmental standards.

Professional Applications & Engineering Value

This 5/16"-18 UNC Class 3A hex headless set screw is engineered to address critical challenges in precision assembly and machinery. The 18-8 stainless steel material offers exceptional corrosion resistance, making it suitable for outdoor, marine, or chemically exposed settings. Its coarse UNC thread and Class 3A fit provide superior holding power, reducing the risk of loosening under vibration—common in automotive, aerospace, and manufacturing equipment. The nylon tip is a key innovation, preventing surface damage on shafts, gears, or pulleys while maintaining positional accuracy. This combination of durability, ease of installation, and protective design ensures reliable performance in high-stress industrial applications, minimizing maintenance and downtime.

Specification Summary & Compliance

This set screw features a 5/16"-18 UNC coarse thread with Class 3A precision tolerance for secure fastening. 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.