| PSC | Description |
|---|---|
| 2805 | Gas Reciprocating Engines, Except Aircraft |
| 2810 | Gas Reciprocating Engines, Aircraft |
| 2815 | Diesel Engines and Components |
| 2820 | Steam Engines, Reciprocating and Components |
| 2825 | Steam Turbines and Components |
| 2830 | Water Turbines, and Water Wheels and Components |
| 2835 | Gas Turbines and Jet Engines, except Aircraft |
| 2840 | Gas Turbines and Jet Engines, aircraft |
| 2845 | Rocket Engines and Components |
| 2850 | Gasoline Rotory Engines and Components |
| 2895 | Miscellaneous Engines and Components |