A pipe crimping tool includes a positioning unit including a positioning base defining therein a positioning space and having a connection portion and a first side arm amd a second side arm respectively extended from two opposite ends of the connection portion in parallel and respectively terminating in a first stopper and a second stopper, two position-limit members respectively disposed at the first side arm and the second side arm at a bottom side, a connection unit pivotally connected to the first stopper and lockable to the second stopper to close the passage of the positioning space, and a hydraulic cylinder connected to the positioning base to hold a pressure block in the positioning space and operable to move the pressure block in achieving a crimping operation.

A press jaw has a drive press jaw and a replaceable press insert which can be coupled thereto, to a drive press jaw having coupling elements, to a press insert having a coupler which can be used as a press jaw insert or as a press loop, and to a system for pressing fittings with tubes, having a modular design with a press jaw, at least two press inserts with different diameters, and a tension insert, wherein the tension insert and the drive press jaw form a tension jaw.