DP-920GH thermal friction drill (also known as high speed sheet metal tapping drill) is the high speed version of DP-920G.
This kind of drill is used in any application where the material is thinner than average applications call for, such as sheet metal or pipe where the material does not have enough support for a threaded surface or a sleeve bearing application.
The high rpm (up to 4000) generates heat to make the material soft, as the drill bit contacts the material, it’s easily pushed through. Some of the melted material is pushed upwards through the hole and forms a collar around the upper surface of the work piece. The rest of the material is being pushed down and forms a bushing in the lower surface of the work piece.
The entire tapping process is completed in seconds. The resulting collar and bushing can be up to 3 times to the original material thickness. The diameter of the bushing depends on the size of the drill bit. The pushing process does not destroy or damage the inner structure of the material but as a result, form a very strong bushing which can be used for threading and bearing sleeves.