Since 1969, Shear-Loc Products has proudly manufactured the Original Quality Instant Thumbscrew. The Shear-Loc process is a unique and cost effective way to convert standard socket head cap screws into instant thumbscrews. Our product is available to you three ways: Knobs Only - where you can cold form the knob on to your own socket head cap screw or custom made screw machine part by means of a vice, arbor press or other suitable assembling device. Thumbscrews - complete units where the knob and screw are factory assembled to your specifications and are ready for use. Knob Kits - allow you to always have a supply of instant thumbscrews on hand, perfect for R&D maintenance and machine shop applications.