S-90291A849 4-40 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, vibration-resistant fastening achieved through Class 3A thread fit for secure assemblies
• Non-marring surface protection from the green nylon 6/6 plastic tip, preventing damage to components
• Reliable performance across extreme temperatures with a tip rated from -50° to 250°F
• Easy installation and removal using the .050" hex drive, even in confined spaces
• Enhanced durability with Rockwell B80 hardness for long service life
• Wide industry acceptance through compliance with ASME B18.3, RoHS 3, and REACH standards

Professional Applications & Engineering Value

This 4-40 UNC thread set screw delivers exceptional engineering value in precision assembly applications. The 18-8 stainless steel construction provides excellent corrosion resistance, making it suitable for demanding environments like machinery, electronics, and automotive components. The headless design with hex drive allows for flush mounting in tight spaces, while the nylon 6/6 plastic tip prevents galling and surface damage to sensitive parts. With its Class 3A thread fit and coarse UNC threading, it ensures reliable, vibration-resistant fastening that maintains integrity under dynamic loads. These features make it an ideal solution for securing collars, pulleys, and gears where precision and durability are critical.

Specification Summary & Compliance

This set screw features a 4-40 UNC thread size with Class 3A thread fit for precise dimensional accuracy. It meets ASME B18.3 manufacturing specifications and complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe and sustainable use in industrial applications worldwide.