S-91185A233 4-40 x 1/4" Thumb Screws

Key Features & Benefits at a Glance

• Enhanced grip and comfort with knurled acetal plastic head for secure manual tightening without tools
• Superior corrosion resistance from 18-8 stainless steel construction, ideal for demanding environments
• Precise thread engagement with Class 3A fit for reliable, vibration-resistant assemblies
• Low-profile design saves space while providing ample thumb pressure surface
• Wide temperature tolerance (32° to 180°F) ensures stable performance across various operating conditions
• Full threading allows maximum adjustment range and consistent clamping force
• Regulatory compliance with RoHS 3 and REACH standards for safe, environmentally conscious manufacturing

Professional Applications & Engineering Value

This 4-40 UNC low-profile thumb screw combines the durability of 18-8 stainless steel with the ergonomic advantages of a knurled acetal plastic head, addressing common assembly challenges in electronics, instrumentation, and machinery. The coarse UNC thread and Class 3A thread fit ensure quick installation and high vibration resistance, reducing maintenance needs in frequently adjusted components. Its fully threaded design provides consistent holding power along the entire 1/4" length, while the low-profile round head minimizes protrusion in compact spaces. Ideal for applications requiring frequent manual access without compromising on corrosion resistance or regulatory compliance.

Specification Summary & Compliance

Manufactured to UNC 4-40 coarse thread specifications with Class 3A thread fit for precision tolerance. Features right-hand threading and fully threaded 1/4" length. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards. Materials include 18-8 stainless steel shaft and acetal plastic head with knurled texture for optimal usability.