1. Key.
 2. Jack.
 3. Jack-operating spring.
 4. Cushion limiting rebound of jack.
 5. Under-hammer.
 6. Hammer-butt.
 7. Hinge of hammer-butt.
 8. Hammer-shank.
 9. Hammer head.

10. Check.
11. Damper-lifter.
12. Damper-head.
13. Action-beam.
14. Wrest-plank.
15. Tuning pins.
16. Bearing-bridge.
17. String.