| 摘要 |
The present invention relates to a screw joint for a drill run or drill string for percussion rock drilling, comprising male and female screw threads ( 5, 9 ) on the elements ( 1, 2 ) to be joined together to form a drill string. According to the invention the male thread ( 5 ) and the female thread ( 9 ) have a trapezoidal shape and a slight conical inclination.
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