Continuous Rim

A masterpiece of construction, a grand piano’s rim is one of the first aspects of the instrument that catches the eye.

Steinway’s innovative continuous rim is notable for the strength and durability it creates, giving these extraordinary instruments the clear and resonant tone that Steinway is known for. Let’s take a look at how a grand’s continuous rim is constructed and why it makes a Steinway different.

What is a grand piano’s rim?

The piano’s rim is a thick piece of wood that wraps around the soundboard. The rims of many older pianos were constructed using several sections held together by joints. While functional, the use of several separate sections of wood weakens the rim’s construction.

As a Steinway needs to carry up to 46,000 pounds of tension, its rim needs to be strong enough to provide adequate support whilst enhancing the acoustic piano’s sound quality. That’s why Steinway instruments are constructed using a continuous rim. Made from one single section of layered laminations of maple, the continuous rim creates a rigid box-like structure that the soundboard fits into, helping enhance the sound of the piano.

The function of the rim is not only to encapsulate the piano’s soundboard but to improve the instrument’s tone by bouncing soundwaves back into the belly of the piano. The specific materials and processes used by Steinway to create the continuous rim are designed to improve these functions, creating the distinctive Steinway sound.

What is a grand piano`s rim - photo by Steinway & Sons

How a piano’s continuous rim is constructed

The construction of a Steinway begins with the rim. A fundamental component of the grand piano and one of the most visually dramatic, experts craft the rim by hand with care and precision. Steinway artisans learn the craft from their masters, passing the skill through the generations to offer unrivalled levels of experience.

Steinway’s unique continuous rim design and process were patented in 1878, influencing the construction of pianos for decades to come. All Steinway components are crafted from the best materials, with the rim using straight-grained, hard-rock maple.

First, this wood is laminated and glued together in flat-grained sets. Next, the inner and outer rims are bent simultaneously, providing improved strength and durability, using a patented Steinway press. Starting from the centre, numerous craftspeople tighten the clamps to create the curved Steinway rim. Being one piece, the curvature distributes the scale tension uniformly through the whole length.

After bending, the rims are stored upright in a conditioning room for a number of months, with the time frame varying depending on the rim’s size. This curing process helps stabilise the shape, form and moisture content. Once the rim is ready, it is trimmed down to the right width and height based on the specifications of its model. As the rim is produced by hand, each will be slightly different, which is why each Steinway is crafted as a unique instrument.

How a piano`s continuous rim is constructed - photo by Steinway & Sons

How the continuous rim sets Steinway pianos apart

From a dedication to only selecting the highest quality materials to its unique and often patented construction techniques, there are numerous factors that contribute to Steinway & Son’s status as the producer of the best pianos in the world. What truly sets Steinway apart is its commitment to continuous improvement; in recent years, the process of creating the iconic continuous rim has been adapted to include reinforced clamping cauls, pneumatic wrenches and Programmable Logic Controlled Conditioning Rooms to optimise curvature, shape, and Steinway’s superior sound quality.


What is the rim on a piano?

The rim on a piano is the curved outer frame that surrounds the soundboard. This is made of wood and is cut to fit the soundboard. It is designed to be strong as to support the tension in the piano and reflects the soundwaves back into the soundboard so no tonal quality is lost.

Why is a piano curved?

Grand pianos are curved because one side’s strings are shorter than the other. The left edge is long and straight, whereas the right side is shorter and curved because the bass strings on the left are longer than the shorter treble strings on the right.

How long is the rim in the press of a piano?

After a piano’s rim is curved, it is left in the press for around 24 hours before being moved to a conditioning room for curing.

What is the distance from the floor to the rim of a grand piano?

The distance is dependent on the model of Steinway you choose.