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                                             
|Alexander Socket Screws Limited                |  | 100.0                                           | % |  | United Kingdom                                      
|Avibank Mfg., Inc                              |  | 100.0                                           | % |  | Delaware                                            
|Avibank Services, LLC                          |  | 85.0                                            | % |  | Delaware                                            
|BI, Inc.                                       |  | 100.0                                           | % |  | Canada                                              
|Caledonian Alloys (China) Ltd.                 |  | 100.0                                           | % |  | China                                               
|Caledonian Alloys France SAS                   |  | 100.0                                           | % |  | France                                              
|Caledonian Alloys Group Ltd.                   |  | 100.0                                           | % |  | United Kingdom                                      
|Caledonian Alloys, Inc.                        |  | 100.0                                           | % |  | South Carolina                                      
|Caldedonian Alloys Ltd.                        |  | 100.0                                           | % |  | United Kingdom                                      
|Caledonian Alloys sro.                         |  | 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 SA                                     |  | 100.0                                           | % |  | France                                              
|Daido Special Metals Ltd.                      |  | 100.0                                           | % |  | Japan                                               
|Environment-One Corporation                    |  | 100.0                                           | % |  | New York                                            
|Fabricas Non-Ferrous S.A. de C.V.              |  | 100.0                                           | % |  | Mexico                                              
|General Valve Company Limited                  |  | 100.0                                           | % |  | United Kingdom                                      
|General Valve of Canada, Inc.                  |  | 100.0                                           | % |  | Canada                                              
|Greengrove Welding Wires Limited               |  | 100.0                                           | % |  | United Kingdom                                      
|Greenville Metals, Inc.                        |  | 100.0                                           | % |  | Pennsylvania                                        
|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                                            
|Incotherm Ltd.                                 |  | 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                                               
|M. Argueso & Co., Inc.                         |  | 100.0                                           | % |  | Delaware                                            
|Mecair Aerospace Industries, Inc.              |  | 100.0                                           | % |  | Canada                                              
|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-Shel 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 Business Trust                                |  | 100.0 | % |  | Delaware      
|PCC CZ s.r.o.                                     |  | 100.0 | % |  | Czech Republic
|PCC European Holdings Sarl                        |  | 100.0 | % |  | Luxembourg    
|PCC European Luxembourg Holdings SCS              |  | 100.0 | % |  | Luxembourg    
|PCC Beheer B.V.                                   |  | 100.0 | % |  | Netherlands   
|PCC European Finance Luxembourg Sarl              |  | 100.0 | % |  | Luxembourg    
|PCC Flow Technologies (Switzerland) AG            |  | 100.0 | % |  | Switzerland   
|PCC Flow Technologies Holdings, Inc.              |  | 100.0 | % |  | Delaware      
|PCC Flow Technologies Limited                     |  | 100.0 | % |  | United Kingdom
|PCC Flow Technologies, Inc.                       |  | 100.0 | % |  | Delaware      
|PCC Flow Technologies Penberthy Canada, Inc.      |  | 100.0 | % |  | Delaware      
|PCC France S.a.r.l.                               |  | 100.0 | % |  | France        
|PCC Johns Landing LLC                             |  | 100.0 | % |  | Delaware      
|PCC Luxembourg Holdings LLC                       |  | 100.0 | % |  | Delaware      
|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 Flow Technologies GmbH                        |  | 100.0 | % |  | Germany       
|PCC Holding B.V.                                  |  | 100.0 | % |  | Netherlands   
|PCC Wouter Witzel Limited                         |  | 100.0 | % |  | United Kingdom
|PCC Specials B.V.                                 |  | 100.0 | % |  | Netherlands   
|PCC Unit I B.V.                                   |  | 100.0 | % |  | Netherlands   
|PCC Unit II B.V.                                  |  | 100.0 | % |  | Netherlands   
|Hamilton Aviation, Inc.                           |  | 100.0 | % |  | Oregon        
|Precision Founders, Inc.                          |  | 100.0 | % |  | California    
|Precision MO Corp                                 |  | 100.0 | % |  | Oregon        
|Precision PL Corp                                 |  | 100.0 | % |  | Oregon        
|Reisner Metals, Inc.                              |  | 100.0 | % |  | California    
|Schulz Wo GmbH                                    |  | 100.0 | % |  | Germany       
|Shur-Lok International                            |  | 100.0 | % |  | Belgium       
|S.M.T., Limited                                   |  | 100.0 | % |  | Ireland       
|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., Ltd.                             |  | 100.0 | % |  | China         
|SPS Hi-Tek Limited                                |  | 100.0 | % |  | Ireland       
|SPS International                                 |  | 100.0 | % |  | Taiwan        
|SPS International Investment Company              |  | 100.0 | % |  | Delaware      
|SPS International Limited                         |  | 100.0 | % |  | Ireland       
|SPS International S.a.r.l.                        |  | 100.0 | % |  | Luxembourg    
|SPS International Trading (Shanghai) Co., Limited |  | 100.0 | % |  | China         
|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 Ltd.                   |  | 100.0 | % |  | Singapore     
|Special Metals Services BV                        |  | 100.0 | % |  | Netherlands   



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|                                                  |  |       |   |  |               
|------------------------------------------------- |  | ----- | - |  | --------------
|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
|Standco Canada Ltd.                               |  | 100.0 | % |  | Canada        
|T.J. Brooks Ltd.                                  |  | 100.0 | % |  | United Kingdom
|Technova GmbH                                     |  | 100.0 | % |  | Germany       
|Unbrako Limited                                   |  | 100.0 | % |  | United Kingdom
|Unbrako, LLC                                      |  | 100.0 | % |  | Delaware      
|Unbrako Mexicana S.A. de C.V.                     |  | 100.0 | % |  | Mexico        
|Unbrako Products (Singapore), Limited             |  | 100.0 | % |  | Singapore     
|Unbrako Pty., Limited                             |  | 100.0 | % |  | Australia     
|Unbrako Schrauben, GmbH                           |  | 100.0 | % |  | Germany       
|Western Aerospace Limited                         |  | 100.0 | % |  | Australia     
|Western Australian Specialty Alloys, Pty. Limited |  | 100.0 | % |  | Australia     
|Wyman-Gordon (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 SC, Inc.                                    |  | 100.0 | % |  | California    
|WG Washington Street, LLC                         |  | 100.0 | % |  | Delaware      
|Udiment Special Metals Ltd.                       |  | 100.0 | % |  | United Kingdom
|Vent-Tek Designs LLC                              |  | 50.0  | % |  | Delaware