Back Off Sub
Brief introduction：
Back off sub can replace taper tap in back-off operation while dealing with stuck accident. When fishing or backing off, if fish is stuck or cannot back-off, it can be withdrawn at the back off sub, and lifts out fishing drill tool.
Specifications:
|
Technical specifications ;
|
Model
|
O.D （mm）
|
Joint thread
（Left-hand thread）
|
Fishing thread
（Right-hand thread）
|
Tensile strength
KN
|
Torsional Strength
KN/M
|
|
DJT105
|
105
|
2 7/8IF
|
2 7/8″IF
|
500
|
9
|
|
DJT121
|
120
|
NC38
|
NC38
|
900
|
15
|
|
DJT159
|
159
|
NC50
|
NC50
|
1500
|
35
|
|
DJT165
|
165
|
NC50
|
NC56 5-1/2FH
|
1900
|
45
|
|
DJT178
|
178
|
5 1/2″FH、NC50
|
5 1/2″FH NC50
|
2000
|
50
|
|
DJT197
|
197
|
6 5/8″ REC
|
6 5/8 ″REC
|
2500
|
65
|
|
|
