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塔形钻头是矿山深孔凿岩的一种重要工具。我矿从一九六五年以来就大量推广使用,但是这种钻头我们以往不能生产,需要向外订货。这样做结果不但成本高,而
Tower bit is an important tool for mining deep hole drilling. My mine has been widely used since 1965, but we have not been able to produce such drill bits and need to order outwards. The result is not only costly, but