| PSC | Description |
|---|---|
| 2805 | Gas reciprocating eng - except air |
| 2810 | Gas reciprocating eng - aircraft |
| 2815 | Diesel engines & components |
| 2820 | Steam engines reciprocating & comps |
| 2825 | Steam turbines & components |
| 2830 | Water turbines,water wheels & comps |
| 2835 | Gas turbines & jet eng except air |
| 2840 | Gas turbines & jet engines aircraft |
| 2845 | Rocket engines & components |
| 2850 | Gasoline rotory engines & comps |
| 2895 | Misc engines & components |