##### 



Exhibit 21.1


Subsidiaries of Hydril Company


Percentage of Voting Securities Owned by Hydril Company


|                                                    |                                                                      |                                                  |       |      |       |    
|--------------------------------------------------- | -------------------------------------------------------------------- | ------------------------------------------------ | ----- | ---- | ----- | ---
|Hydril General LLC (Delaware)                       |                                                                      |                                                  | 100%  |     
|                                                    | Hydril Company LP (Delaware)                                         |                                                  |       | 1%   |      
|Hydril Limited LLC (Delaware)                       |                                                                      |                                                  | 100%  |     
|                                                    | Hydril Company LP (Delaware)                                         |                                                  |       | 99%  |      
|                                                    |                                                                      | Hydril Jindal International Private Ltd. (India) |       |      | 50%   | (5)
|Hydril India JV, LLC (Delaware)                     |                                                                      |                                                  | 100%  |     
|                                                    | Hydril India Private Ltd. (India)                                    |                                                  |       | 49%  | (6)  
|Hydril Acquisition Sub, Inc. LP (Delaware)          |                                                                      |                                                  | 100%  |     
|                                                    | 3084408 Nova Scotia Company                                          |                                                  |       | 100% |      
|                                                    |                                                                      | RF Ironworks Limited Partnership                 |       |      | 99%   | (1)
|                                                    |                                                                      | Hydril Canadian Company Limited Partnership      |       |      | 99.9% | (4)
|                                                    |                                                                      | 3078778 Nova Scotia Company                      |       |      | 100%  |    
|                                                    |                                                                      | 3083489 Nova Scotia Company                      |       |      | 100%  |    
|Hydril S.A. (Switzerland)                           |                                                                      |                                                  | 53%   | (2) 
|Hydril U.K. Ltd. (England, U.K.)                    |                                                                      |                                                  | 100%  |     
|                                                    | Panelglen, Ltd. (England, U.K.)                                      |                                                  |       | 100% |      
|                                                    |                                                                      | Flowguard, Ltd. (England, U.K.)                  |       |      | 100%  |    
|Hydril Private Ltd. (Republic of Singapore)         |                                                                      |                                                  | 100%  |     
|                                                    | Technical Drilling & Production Services Nigeria, Ltd.
    (Nigeria) |                                                  |       | 60%  |      
|                                                    | P.T. Hydril Indonesia                                                |                                                  |       | 99%  | (3)  
|Hydril S.A. de C.V. (Mexico)                        |                                                                      |                                                  | 100%  |     
|Bettis de Mexico S.A. de C.V. (Mexico)              |                                                                      |                                                  | 100%  |     
|Hydril Pressure Control S. de R.L. de C.V. (Mexico) |                                                                      |                                                  | 99.6% | (7) 






|    |                                                                                                                        
|--- | -----------------------------------------------------------------------------------------------------------------------
|(1) | 3078778 Nova Scotia Company owns the remaining 1% equity
    interest in RF Ironworks Limited Partnership.             
|   
|(2) | Hydril Private Ltd. owns the remaining 47% equity interest in
    Hydril S.A.                                          
|   
|(3) | Hydril Company owns the remaining 1%.                                                                                  
|   
|(4) | 3083489 Nova Scotia Company owns the remaining 0.1% equity
    interest in Hydril Canadian Company Limited Partnership.
|   
|(5) | Joint venture 50% owned by Hydril Company LP.                                                                          
|   
|(6) | Joint venture 49% owned by Hydril India JV, LLC.                                                                       
|   
|(7) | Hydril Acquisition Sub, Inc. owns the remaining 0.4%.