| 29 / | HD | METAL WORKING |
| 592 | DF | METHOD OF MECHANICAL MANUFACTURE {54} |
| 888 | DF | .~ Prime mover or fluid pump making {12} |
| 888.4 | DF | .~.~ Poppet or I.C. engine valve or valve seat making {6} |
| 888.45 | DF | .~.~.~ Composite or hollow valve stem or head making {3} |
| 888.453 | ![]() | .~.~.~.~ Including casting |