Press-In Inserts for Plastics
Press-In inserts are designed to be pressed into a straight hole without melting the plastic prior to installation. Ideal for use in softer plastics, the helical knurls of the press-in inserts are used to provide both torque and pull-out resistance and to ensure good plastic flow as the insert rotates into the hole. Installation torque to achieve sufficient tension between the threads is not a problem in that the helical knurls are designed so that the direction of the installation torque will have the tendency to drive the insert into the hole — which of course is not possible — as the threaded joint is tightened. A pilot only slightly smaller than the hole and of sufficient length is designed to assure straight insertion into the hole. Press-in inserts offer rapid installation with no specialized equipment and achieve good overall joint performance.