Junk Mill Type MXP can be divided into three kinds: flat-bottom (or concave_bottom) milling shoe, guide milling shoe and cone milling shoe, according to its structure and shape. At the milling surface, the carbide particles are built up by welding, which plays a part of self_milling. It is used to mill the fallen substances, such as tooth wheel, slipdog, fittings for deep_well pump, etc. with the advantages of anti impact and longer service life.