A Jack Screw is simply a 3/16” Hex, 4-40 Male-Female Standoff, that is 3/16” in length. What separates these is that you can choose the male-thread length that will best fit your application. These are also called Female Screw-Locks and are most commonly used in mounting D-Sub Connectors. Each Jack Screw is available as a stand-alone screw, but visit the Jackscrew Assembly and Jack Screw Bulk Kit Sections to purchase the complete set of mounting hardware. The hex shape allows for greater torquing as the flat sides allow for wrench tightening. Steel is inexpensive, easy to achieve finer surface quality requirements and provides relatively high strength properties. Multiple plating options are available to increase the material's corrosion resistance and alter its appearance.