The quality standards for the ribs must align precisely with those required for the soundboard, as they are integral to its function. The ribs distribute vibrations uniformly across the soundboard, stabilize its structure, and enable it to endure the tension exerted by the strings. The ribs are affixed to the gluing bed of the soundboard, which is slightly planed with a convex profile. This ensures the desired curvature of the soundboard is achieved. Ideally, there should be no fewer than eight ribs, extending across the inner strip. Their design must match perfectly with the gluing surface, which typically features grooves to secure the ribs. The dimensions and shapes of the ribs vary by manufacturer, tailored to the specific instrument design. In an upright piano of 100 cm height, the cumulative length of the ribs is approximately 8.50 meters; in a 130 cm upright, it increases to about 10.00 meters, and for a 200 cm grand piano, it is approximately 9.60 meters. Depending on the piano's size, the number of ribs typically ranges from 8 to 12. They are oriented orthogonally to the grain of the soundboard and glued using moisture-resistant adhesives. In certain cases, they are additionally fastened with screws.

For new instruments, before string installation, the convexity of the soundboard is calibrated. Transverse measurements from the fiber grain reveal a height differential of 5 mm at the apex, while longitudinal measurements show a 7 mm differential. In refurbished instruments, string tension adjustments are required: 1–2 mm in the treble, 2–3 mm in the midrange, and approximately 2 mm in the bass. Before sanding, the veneer is moistened to ensure optimal adhesion of the fibers along the edges. Following this step, the soundboard components are dried, sanded, and cleaned in preparation for surface finishing. Varnish is applied in multiple layers, with sanding performed between coats to ensure a smooth finish.

The grill beams, case, soundboard, and ribs are shaped and precisely joined. Once the components are glued, the grill sides are cut parallel to a uniform depth. Soundboards are supplied as square boards, free of ribs and bridges, and are seasoned with wooden spacers to facilitate air circulation. They are later transferred to drying chambers for final conditioning. The ribs are shaped into a curve to induce the soundboard’s convexity, then trimmed to exact lengths with tapered ends to maintain the elasticity of the assembly.

Bass and treble bridges are machined to specification. Subsequent processes, controlled by advanced computer systems, ensure proper alignment, create pinholes, and refine bridge profiles. These systems guarantee accuracy and consistency across all bridge components. During assembly, the bridges and ribs are affixed to the soundboard. The bridges are coated with adhesive and positioned face down; the soundboard is placed on top, and the ribs are glued in sequence. A hydraulic press applies uniform pressure until the adhesive cures completely. Afterward, the bridge pins are masked, and the soundboard is spray-painted. It undergoes sanding between paint applications to achieve a flawless finish. Finally, the soundboard is bonded to the piano's grill, and the cast iron frame is installed. The iron plates, sourced from specialized foundries, are drilled, painted, and fitted with tuning pin buttons. A dense felt strip is adhered in front of the plate pins and thinned to regulate the string load on the soundboard. These steps ensure precision and contribute to the structural integrity and tonal quality of the instrument.