These Knurled Inserts for Thicker Panels have tiny knurls under their head, and are designed to be installed into most materials over .030in/.76mm in thickness. Their reduced length makes them ideal for limited clearance applications. They can be installed using lightweight, handheld pneumatic tools that can be located at any position in your assembly sequence. As the insert is installed, the threaded nut portion is drawn into the upper sleeve portion. This 360º swaging action expands the sleeve to firmly hold the insert in position in the hole. They are to be used with Grade 8/Metric 12.9 mating screws. These inserts are available with standard open ends, or closed ends to prevent leakage past the threads from either side of the application. (For information on a design option with no knurls under the head, please contact EFC International directly.)