S-90165A418 1/4"-20 x 3 1/2" Thumb Screws

Key Features & Benefits at a Glance

• Effortless hand-tightening with a large four-arm thumb head (1 1/8" width) for quick assembly and disassembly without tools.
• Superior corrosion resistance provided by the black-oxide steel finish, extending service life in demanding industrial environments.
• Exceptional mechanical strength with a tensile strength of 180,000 psi and Rockwell C40 hardness for reliable, heavy-duty fastening.
• Secure and adaptable fastening thanks to the removable swivel tip, which accommodates a 10° maximum angle to prevent component damage.
• Reliable thread engagement with a coarse UNC 1/4"-20 thread and Class 2A fit, ensuring consistent performance and easy starting.
• Full-length threading for maximum grip and adjustability along the entire 3 1/2" length of the screw.
• Compliance with global standards, being RoHS 3 and REACH compliant for safe use in regulated industries.

Professional Applications & Engineering Value

This black-oxide steel thumb screw is engineered to solve common industrial fastening challenges where tool-less operation and high strength are critical. The four-arm head design provides excellent leverage for manual tightening in confined spaces or on frequently adjusted equipment. The removable swivel tip is a key feature for applications involving uneven surfaces or delicate materials, as it distributes pressure evenly and minimizes the risk of marring or damage. With its coarse UNC thread and Class 2A thread fit, it offers quick assembly and reliable holding power in machinery, electronic enclosures, and jig and fixture setups. The robust 180,000 psi tensile strength ensures it can withstand significant vibrational and dynamic loads, making it a dependable choice for industrial thumb screws in maintenance, manufacturing, and automation sectors.

Specification Summary & Compliance

This thumb screw adheres to UNC thread standards with a 1/4"-20 thread size and Class 2A thread fit for precise dimensional accuracy. It is fully threaded and features a right-hand thread direction. The product is manufactured to be RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, ensuring it meets stringent environmental and safety regulations for industrial use.