
Specification:
| Size in | Upper box connection | Lower pin connection | ID mm | Driving section mm | |||||||||
| Type(LH) | OD mm | Thread | Four | Six | Cross flat | For square kelly | Cross corner for hexa kelly | ||||||
| Std | Optional | Std | Optional | Four | OD  | Six | OD  | ||||||
| 2 1/2 | 6 5/8REG | 4 1/2REG | 196.8 | 146.0 | NC26 | 85.7 | 
 | 
 | 31.8 | 
 | 63.5 | 83.3 | 
 | 
| 3 | 6 5/8REG | 4 1/2REG | 196.8 | 146.0 | NC31 | 104.8 | NC26 | 85.7 | 44.4 | 31.8 | 76.2 | 100.0 | 85.7 | 
| 3 1/2 | 6 5/8REG | 4 1/2REG | 196.8 | 146.0 | NC38 | 120.6 | NC31 | 104.8 | 57.2 | 44.4 | 88.9 | 115.1 | 100.8 | 
| 4 1/4 | 6 5/8REG | 4 1/2REG | 196.8 | 146.0 | NC46 | 158.8 | NC38 | 120.6 | 71.4 | 57.2 | 108.0 | 141.3 | 122.2 | 
| 6 5/8REG | 4 1/2REG | 196.8 | 146.0 | NC50 | 161.9 | NC38 | 120.6 | 71.4 | 57.2 | 108.0 | 141.3 | 122.2 | |
| 5 1/4 | 6 5/8REG | 
 | 196.8 | 
 | 5 1/2FH | 177.8 | NC46 | 158.8 | 82.6 | 76.2 | 133.3 | 175.4 | 151.6 | 
| 6 5/8REG | 
 | 196.8 | 
 | NC56 | 177.8 | NC50 | 161.9 | 82.6 | 82.6 | 133.3 | 175.4 | 151.6 | |
| 6 | 6 5/8REG | 
 | 196.8 | 
 | 
 | 
 | 5 1/2FH | 177.8 | 
 | 88.9 | 152.4 | 
 | 173 | 
| 6 5/8REG | 
 | 196.8 | 
 | 
 | 
 | NC56 | 177.8 | 
 | 88.9 | 152.4 | 
 | 173 | |

 
  


 
  
  
 