TMK TDS is a thread connection fully compatible with API connections and having two shoulders. During the make-up torque application, the secondary shoulder of the pin comes in contact with the inner shoulder of the box, increasing the contact area, which provides for transmission of higher torque.
This connection is intended for use during well construction and workover, in complicated geological conditions, for drilling wells with high intensity of drift angle build-up.
Standard sizes:
In accordance with GOST 54383, API Spec5DP.
TMK TDS drilling tool joints can be manufactured:
- with right- or left-handed tool joint thread;
- of standard or extended length;
- with a square or tapered shoulder for elevator;
- with necks of standard or increased outer diameter;
- with the option of hard-alloy build-up along the outer diameter of the tool joint.
Additional inner shoulder improves the performance of the thread connection in case of excessive torque, tension. It ensures high flexibility of drilling string.
- Thread pitch is 6.35 mm
- Taper is 1:6
- Stab flank angle is +30˚
- Load flank angle is +30˚
- Triangular taper thread
Opportunity to manufacture in the required version:
- High-strength
- Cold-resistant
- H2S-resistant


Note: the parameters apply to the API standard connections and TMK TDS connections; the same inner and outer diameters have been selected for comparison.
Comparison of tool joint connections
Pipe size (mm) | Thread connection | Tool joint diameter (mm) | Make-up torque | ||
Type | Tool joint | Outer | Inner | (N∙m) | |
60,3 | API | NC 26 | 85,7 | 44,45 | 5532 |
TMK | TMK TDS | 85,7 | 44,45 | 7020 | |
73,0 | API | NC 31 | 104,8 | 50,8 | 10735 |
TMK | TMK TDS | 104,8 | 50,8 | 14100 | |
88,9 | API | NC 38 | 127,0 | 61,91 | 18070 |
TMK | TMK TDS | 127,0 | 61,91 | 24120 | |
101,6 | API | NC 40 | 139,7 | 61,91 | 24500 |
TMK | TMK TDS | 139,7 | 61,91 | 33240 | |
114,3 | API | NC 46 | 158,8 | 76,2 | 32262 |
TMK | TMK TDS | 158,8 | 76,2 | 43980 | |
127,0 | API | NC 50 | 161,9 | 88,9 | 36341 |
TMK | TMK TDS | 161,9 | 88,9 | 49200 | |
139,7 | API | 5½ FH | 184,2 | 88,9 | 58960 |
TMK | TMK TDS | 184,2 | 88,9 | 89340 | |