S-91185A245 4-40 x 5/8" Thumb Screws

Key Features & Benefits at a Glance

• Tool-free manual operation with comfortable Acetal plastic knurled head for quick adjustments and reduced assembly time
• Exceptional corrosion resistance from 18-8 stainless steel construction, ensuring long-term reliability in demanding environments
• Precise thread engagement with Class 3A fit for secure fastening and vibration resistance in critical applications
• Wide temperature compatibility (32° to 180° F) for stable performance across various industrial settings
• Enhanced grip and comfort from the low-profile round head design, minimizing hand fatigue during repeated use
• Full threading coverage along the 5/8" length for maximum holding power and versatility in different material thicknesses
• Regulatory compliance assurance with RoHS 3 and REACH standards, meeting international environmental and safety requirements

Professional Applications & Engineering Value

This 4-40 UNC thumb screw combines the strength of 18-8 stainless steel with the ergonomic advantages of an Acetal plastic knurled head, addressing common industrial challenges like frequent adjustments and corrosion-prone environments. The coarse thread design enables rapid installation in soft materials or pre-tapped holes, while the Class 3A thread fit maintains tight tolerances for vibration-resistant assemblies in electronics, machinery, and instrumentation. Its low-profile round head prevents snagging in confined spaces, making it ideal for access panels, calibration devices, and production equipment where tool-less access is critical. The fully threaded construction ensures consistent clamping force across varying material depths, reducing the need for multiple screw types and simplifying inventory management.

Specification Summary & Compliance

This thumb screw features precision 4-40 UNC coarse threads with Class 3A fit and 0.112" thread diameter, manufactured to standard inch system dimensions including 5/8" length and 5/16" head diameter. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring adherence to environmental and safety standards for industrial components.