| Stuart No. 19, (2002) | Steinway No. 574500,(2005) | |
| Action | Stuart & Sons action Tokiwa made with addition of rare earth magnets between hammer shank and repetition lever. Stuart & Sons balance rail bushings and pin system. | Steinway & Sons action and tubular metallic action frame. Traditionally Steinway manufacture for US models and Renner for German models. Now Renner made for all models |
| Pedals | 4 Pedals : Dolce, Una Corda, Sostenuto & Damper Dolce: reduction of lever motion/dynamics. See pg. chapter 6 for an illustration of the 4 pedals. |
3 pedals : Una Corda, Sostenuto & Damper |
| Hammer shanks | Abel, 5 configurations of stiffness, 2 hexagonal wound strings; 3 oval pure wire C2 5.25mm; C3 5.1mm; C4 4.5mm; C5 4mm, |
Renner, 2 configurations of stiffness hexagonal wound strings and oval pure wire. C2 6mm; C3 4.7 mm; C4 4.7mm; C5 4.7mm; |
| Hammer Felts | Abel to specific design | Renner |
| Hammer strike | angle strike | angle strike |
| Actions, Pedals, Hammers Table 1.3 | ||
The most significant difference in string scale was observed in the lowest frequency, C2 65.406Hz.
