WATER JET MACHINING METHOD FOR HARDLY MACHINABLE MATERIAL

PROBLEM TO BE SOLVED: To provide a machining method causing a machined surface to be smooth even when a workpiece being an object has a small diameter without generating burr or bending and without generating an excessive cutting flaw or the like to another part, in the machining method of cutting the workpiece of a pipe shape formed of a hardly machinable resin such as an engineering plastic or a hardly machinable material such as a composite material using inorganic fiber using a water jet.SOLUTION: An apparatus provided with an impact absorption means inserted into a hollow part of a workpiece to absorb impact by a water current of an injected water jet is used. Cutting machining of a product member having a predetermined size is sequentially performed from an end of the workpiece at a side confronting a support means. A rotational speed of a rotation means and a pressure of the water jet injected by an injection means are adjusted. The cutting proceeds with a cutting depth of ≤0.5 mm during one revolution of the workpiece to perform the cutting.