Exhibit 21

SUBSIDIARIES OF PRECISION CASTPARTS CORP.



|                                               |  |                                                 |   |  |                                                     
|---------------------------------------------- |  | ----------------------------------------------- | - |  | ----------------------------------------------------
|Name of Subsidiary                             |  | ApproximatePercentage of VotingSecurities Owned |   |  | State or Jurisdictionof Incorporation orOrganization
|AAA Aircraft Supply LLC                        |  | 100.0                                           | % |  | Delaware                                            
|A-1 Wire Tech Inc                              |  | 100.0                                           | % |  | Illinois                                            
|Advanced Forming Technology Inc                |  | 100.0                                           | % |  | Colorado                                            
|AETC Limited                                   |  | 100.0                                           | % |  | United Kingdom                                      
|AFT Europa-Advanced Forming Technology Limited |  | 100.0                                           | % |  | Hungary                                             
|AF Aerospace Limited                           |  | 100.0                                           | % |  | United Kingdom                                      
|Airdrome Parts Co Limited                      |  | 100.0                                           | % |  | United Kingdom                                      
|Alexander Socket Screws Limited                |  | 100.0                                           | % |  | United Kingdom                                      
|Avibank Mfg Inc                                |  | 100.0                                           | % |  | Delaware                                            
|Avibank Services LLC                           |  | 85.0                                            | % |  | Delaware                                            
|Caledonian Alloys (Tianjin) Ltd                |  | 100.0                                           | % |  | China                                               
|Caledonian Alloys France SAS                   |  | 100.0                                           | % |  | France                                              
|Caledonian Alloys Group Ltd                    |  | 100.0                                           | % |  | United Kingdom                                      
|Caledonian Alloys (Canada) Ltd                 |  | 100.0                                           | % |  | Canada                                              
|Caledonian Alloys Inc                          |  | 100.0                                           | % |  | South Carolina                                      
|Caledonian Alloys Ltd                          |  | 100.0                                           | % |  | United Kingdom                                      
|Caledonian Alloys s.r.o                        |  | 100.0                                           | % |  | Czech Republic                                      
|Caley Group Ltd                                |  | 100.0                                           | % |  | United Kingdom                                      
|Cameron Forged Products Limited                |  | 100.0                                           | % |  | United Kingdom                                      
|Cannon Muskegon Corporation                    |  | 100.0                                           | % |  | Michigan                                            
|Carmet Investors Inc                           |  | 100.0                                           | % |  | Georgia                                             
|Chevron Aerospace Group Limited                |  | 100.0                                           | % |  | United Kingdom                                      
|Chevron Aerostructures Limited                 |  | 100.0                                           | % |  | United Kingdom                                      
|Cometal SAS                                    |  | 100.0                                           | % |  | France                                              
|Daido Special Metals Limited                   |  | 100.0                                           | % |  | Japan                                               
|Environment One Corporation                    |  | 100.0                                           | % |  | New York                                            
|Fatigue Technology Inc                         |  | 100.0                                           | % |  | Washington                                          
|Fatigue Technology International Corp          |  | 100.0                                           | % |  | Washington                                          
|FTI Manufacturing Inc                          |  | 100.0                                           | % |  | Washington                                          
|General Valve Company Ltd                      |  | 100.0                                           | % |  | United Kingdom                                      
|Greengrove Welding Wires Limited               |  | 100.0                                           | % |  | United Kingdom                                      
|Greenville Metals Inc                          |  | 100.0                                           | % |  | Pennsylvania                                        
|Hackney Ladish Holding Corp                    |  | 100.0                                           | % |  | Delaware                                            
|Hackney Ladish Inc                             |  | 100.0                                           | % |  | Delaware                                            
|Hamilton Aviation Inc                          |  | 100.0                                           | % |  | Oregon                                              
|Hi-Life Tools (UK) Limited                     |  | 100.0                                           | % |  | United Kingdom                                      
|Hi-Life ULMA Srl                               |  | 100.0                                           | % |  | Italy                                               
|Howell Penncraft Inc                           |  | 100.0                                           | % |  | Delaware                                            
|Huntington Alloys Canada Ltd                   |  | 100.0                                           | % |  | Canada                                              
|Huntington Alloys Corporation                  |  | 100.0                                           | % |  | Delaware                                            
|Huntington Revert LLC                          |  | 100.0                                           | % |  | Delaware                                            
|Incotherm Limited                              |  | 100.0                                           | % |  | United Kingdom                                      
|International Extruded Products LLC            |  | 100.0                                           | % |  | New York                                            
|J&L Fiber Services Inc                         |  | 100.0                                           | % |  | Wisconsin                                           
|Kadimi Tool Mfg. Co. PVT Limited               |  | 50.0                                            | % |  | India                                               



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|                                             |  |       |   |  |               
|-------------------------------------------- |  | ----- | - |  | --------------
|M. Argueso & Company Inc                     |  | 100.0 | % |  | Delaware      
|Metalac Fasteners Inc                        |  | 100.0 | % |  | Illinois      
|Metalac S.A. Industria E Commercio           |  | 100.0 | % |  | Brazil        
|Metalac SPS Industria E Commercio, Ltda      |  | 100.0 | % |  | Brazil        
|NSS Technologies Inc                         |  | 100.0 | % |  | Michigan      
|Nutt-Shell Company                           |  | 100.0 | % |  | California    
|Oregon Plasma Melting                        |  | 50.0  | % |  | Oregon        
|Otto Vogeli Industriearmaturen GmbH          |  | 100.0 | % |  | Germany       
|PCC Airfoils S.A. de C.V.                    |  | 100.0 | % |  | Mexico        
|PCC Airfoils LLC                             |  | 100.0 | % |  | Ohio          
|PCC Beheer B.V.                              |  | 100.0 | % |  | Netherlands   
|PCC Business Trust                           |  | 100.0 | % |  | Massachusetts 
|PCC CZ s.r.o.                                |  | 100.0 | % |  | Czech Republic
|PCC European Holdings Sarl                   |  | 100.0 | % |  | Luxembourg    
|PCC Finance Luxembourg Sarl                  |  | 100.0 | % |  | Luxembourg    
|PCC Flow Technologies GmbH                   |  | 100.0 | % |  | Germany       
|PCC Flow Technologies Holdings Inc           |  | 100.0 | % |  | Delaware      
|PCC Flow Technologies Inc                    |  | 100.0 | % |  | Delaware      
|PCC Flow Technologies Limited                |  | 100.0 | % |  | United Kingdom
|PCC Flow Technologies Penberthy Canada Inc   |  | 100.0 | % |  | Delaware      
|PCC France S.a.r.l.                          |  | 100.0 | % |  | France        
|PCC Holding B.V.                             |  | 100.0 | % |  | Netherlands   
|PCC Johns Landing LLC                        |  | 100.0 | % |  | Delaware      
|PCC Luxembourg Holdings LLC                  |  | 100.0 | % |  | Delaware      
|PCC Luxembourg Holdings SCS                  |  | 100.0 | % |  | Luxembourg    
|PCC Specials B.V.                            |  | 100.0 | % |  | Netherlands   
|PCC Specialty Products Inc                   |  | 100.0 | % |  | Delaware      
|PCC Structurals Inc                          |  | 100.0 | % |  | Oregon        
|PCC Unit III B.V.                            |  | 100.0 | % |  | Netherlands   
|PCC Unit IV B.V.                             |  | 100.0 | % |  | Netherlands   
|PCC Unit I B.V.                              |  | 100.0 | % |  | Netherlands   
|PCC Unit II B.V.                             |  | 100.0 | % |  | Netherlands   
|PCC Wouter Witzel Limited                    |  | 100.0 | % |  | United Kingdom
|Precision Founders Inc                       |  | 100.0 | % |  | California    
|Precision MO Corp                            |  | 100.0 | % |  | Oregon        
|Precision PL Corp                            |  | 100.0 | % |  | Oregon        
|Reisner Metals Inc                           |  | 100.0 | % |  | California    
|S.M.T. Limited                               |  | 100.0 | % |  | Ireland       
|Shur-Lok International S.A.                  |  | 100.0 | % |  | Belgium       
|SMW Holdings Limited                         |  | 100.0 | % |  | United Kingdom
|SPS Aerostructures Limited                   |  | 100.0 | % |  | United Kingdom
|SPS Asia Limited                             |  | 100.0 | % |  | Hong Kong     
|SPS Chevron Limited                          |  | 100.0 | % |  | United Kingdom
|SPS (China) Co., Limited                     |  | 100.0 | % |  | China         
|SPS Hi-Tek Limited                           |  | 100.0 | % |  | Ireland       
|SPS International                            |  | 100.0 | % |  | Taiwan        
|SPS International Investment Co              |  | 100.0 | % |  | Delaware      
|SPS International Limited                    |  | 100.0 | % |  | Ireland       
|SPS International S.a.r.l.                   |  | 100.0 | % |  | Luxembourg    
|SPS International Trading (Shanghai) Co. Ltd |  | 100.0 | % |  | China         
|SPS Technologies (Australia) Pty Ltd         |  | 100.0 | % |  | Australia     



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|                                                 |  |       |   |  |               
|------------------------------------------------ |  | ----- | - |  | --------------
|SPS Technologies Limited                         |  | 100.0 | % |  | United Kingdom
|SPS Technologies LLC                             |  | 100.0 | % |  | Pennsylvania  
|SPS Technologies Overseas Holding B.V.           |  | 100.0 | % |  | Netherlands   
|SPS Technologies Trading Limited                 |  | 100.0 | % |  | United Kingdom
|SPS Technologies Trading Pte. Limited            |  | 100.0 | % |  | Singapore     
|SPS Technologies Waterford Company               |  | 100.0 | % |  | Michigan      
|SPS Unbrako K.K.                                 |  | 100.0 | % |  | Japan         
|Special Metals Corporation                       |  | 100.0 | % |  | Delaware      
|Special Metals Deutschland Limited               |  | 100.0 | % |  | United Kingdom
|Special Metals Pacific PTE Limited               |  | 100.0 | % |  | Singapore     
|Special Metals Services BV                       |  | 100.0 | % |  | Netherlands   
|Special Metals Services Limited                  |  | 100.0 | % |  | United Kingdom
|Special Metals Wiggin Limited                    |  | 100.0 | % |  | United Kingdom
|Special Metals Wiggin Trustees Limited           |  | 100.0 | % |  | United Kingdom
|T.J. Brooks Ltd                                  |  | 100.0 | % |  | United Kingdom
|Thistle Processing LLC                           |  | 100.0 | % |  | Delaware      
|Unbrako Limited                                  |  | 100.0 | % |  | United Kingdom
|Unbrako LLC                                      |  | 100.0 | % |  | Delaware      
|Unbrako Mexicana S.A. de C.V.                    |  | 100.0 | % |  | Mexico        
|Unbrako Products (Singapore) Pte. Ltd            |  | 100.0 | % |  | Singapore     
|Unbrako Schrauben GmbH                           |  | 100.0 | % |  | Germany       
|Western Aerospace Limited                        |  | 100.0 | % |  | Australia     
|Western Australian Specialty Alloys Pty. Limited |  | 100.0 | % |  | Australia     
|Wyman Gordon de Mexico S. de R.L. de C.V.        |  | 100.0 | % |  | Mexico        
|Wyman Gordon Forgings (Cleveland) Inc            |  | 100.0 | % |  | Ohio          
|Wyman Gordon Company                             |  | 100.0 | % |  | Massachusetts 
|Wyman Gordon Composites Technologies Inc         |  | 100.0 | % |  | California    
|Wyman Gordon Forgings Inc                        |  | 100.0 | % |  | Delaware      
|Wyman Gordon Investment Castings Inc             |  | 100.0 | % |  | Delaware      
|Wyman Gordon Limited                             |  | 100.0 | % |  | United Kingdom
|Wyman Gordon (Lincoln) Limited                   |  | 100.0 | % |  | United Kingdom
|Wyman Gordon Monterrey S. de R.L. de C.V.        |  | 100.0 | % |  | Mexico        
|Wyman Gordon s.r.o.                              |  | 100.0 | % |  | Czech Republic
|Wyman Gordon SC Inc                              |  | 100.0 | % |  | California    
|Wyman Gordon Washington Street LLC               |  | 100.0 | % |  | Delaware      
|Vent-Tek Designs LLC                             |  | 50.0  | % |  | Delaware