S-99607A239 1/4"-28 x 1/2" Thumb Screws

Key Features & Benefits at a Glance

• Enhanced Grip and Torque Application: Knurled head texture provides superior manual handling, reducing slippage during installation and removal in tight spaces.
• Exceptional Corrosion Resistance: Made from 18-8 Stainless Steel, offering reliable performance in humid, chemical, or outdoor environments without rusting.
• High Mechanical Strength: With a tensile strength of 80,000 psi and Rockwell B85 hardness, it withstands heavy-duty loads and repeated use without deformation.
• Precision Thread Fit for Secure Fastening: Class 2A thread fit ensures consistent, vibration-resistant connections, minimizing loosening in dynamic applications.
• Flared Collar Design for Surface Protection: The round-head with flared collar distributes pressure evenly, preventing damage to sensitive surfaces during tightening.
• Full Threading for Maximum Engagement: Fully threaded 1/2" length allows for adjustable depth and strong holding power across various material thicknesses.
• Compliance with Environmental Standards: RoHS 3 and REACH compliant, ensuring safe use in regulated industries and reducing environmental impact.

Professional Applications & Engineering Value

This 1/4"-28 UNF knurled thumb screw is engineered to address common industrial challenges, such as tool-free maintenance and corrosion in harsh conditions. The 18-8 Stainless Steel construction provides excellent resistance to oxidation and chemicals, making it ideal for electronics enclosures, machinery panels, and marine equipment. The fine UNF threads and Class 2A fit deliver precise, reliable fastening that resists vibration loosening, while the knurled head and flared collar enhance ergonomic handling and protect surfaces from marring. By integrating these features, it streamlines assembly processes, reduces downtime, and ensures long-term durability in industrial thumb screw applications.

Specification Summary & Compliance

This thumb screw adheres to UNF fine thread standards with a Class 2A thread fit for consistent dimensional accuracy. It meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring it is free from hazardous substances. Key specifications include a thread size of 1/4"-28, full threading, and a right-hand thread direction, manufactured to support reliable performance in precision assemblies.