| 摘要 |
The invention provides a practical perforating tool with environmental protection and low cost. The perforating tool comprises a main body (1) and a handle portion (3). The main body has an edge portion (2) which is provided with one or a plurality of chip removal grooves which extend from the tip of the tool and face the base end side at the periphery of the main body. The handle portion is provided with a handle portion body (15) having a diameter larger than that of the edge portion (2) at the base end side. The edge portion (2) is composed by superhard alloy components containing tungstencarbide and cobalt, and the handle portion (3) is composed by stainless steel components. The superhard alloy components and the stainless steel components are connected through welding. A step portion (4) is disposed between the edge portion (2) and the handle body (15). The external diameter of the middle part of the step portion is larger than that of the edge portion (2) and is smaller than that of the handle body (15). The external diameter of the step portion (4) is set in a manner that the external diameter will periodically or continuously increase as the step portion approaches to the base end side. |
