| 摘要 |
This invention relates to the branch of drill engineering and can be used in mining, coal extraction and oil-producing industries. The drill beam has shell and connected to it muff with inner conical threading at the free end and nipple with outer conical threading at the free end. The threading is arranged as special locking with pitch mm, angle of the profile at profile height h= (7...12) mm, at that the diameter of the larger base of the cone dp is related to the outer diameter of the beam D through relation dp at D values between 63 mm and 245 mm, and the inner diameter of the beam d is related to the diameter of the larger base of the cone by relation d ? (0,8...0,9) dp. At the outer surface of the beam near each of its ends two pairs of mutually normal flats are arranged.
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