在普通钻铤或螺旋钻铤的内螺纹端外表面上加工吊卡槽和卡瓦槽起下钻时就可不用提升短节和安全卡瓦，吊卡槽和卡瓦槽的尺寸符合API Spec7-1标准，钻铤的耐磨带是可选的。
Drill Collar With Slip Groove
Slip groove made on box thread face of slick collar can be used as lifting sub and safely slip when trip out. The technical parameters for slip groove are as per API spe. 7-1. Hardbanding is optional at customers’' request.
钻铤的机械性能
外径范围mm | 屈服强度Mpa | 抗拉强度Mpa | 伸长率 | 布氏硬度 HB | 夏比冲击功 |
79.4～171.4 | ≥758 | ≥965 | ≥13 | 285～341 | ≥54 |
177.8～279.4 | ≥689 | ≥930 | ≥13 | 285～341 | ≥54 |
