Keyboard weight of keyboard instrument, key attached with keyboard weight, and method of attaching keyboard weight

A keyboard weight immovably attached in an inserted state to a penetrating embedding hole having a predetermined diameter formed in a key of a keyboard instrument, the keyboard weight comprising:

• a weight main body that is made of a material other than lead and is formed in a columnar shape having a predetermined diameter and a predetermined length;
• and
• a hollow member that is made of a material other than lead, is formed in a cylindrical shape having an inner diameter allowing the weight main body to be inserted into the hollow member, an outer diameter allowing the hollow member to be inserted into the embedding hole, and a predetermined length longer than the weight main body, and is inserted into the embedding hole in a state where the weight main body is inserted inside when the keyboard weight is attached to the key, wherein
• the hollow member is provided with a thin portion that extends along an entire circumferential direction, has a predetermined width in a length direction, and has a predetermined thickness smaller than a thickness of the other portion of the hollow member, and
• the hollow member is configured such that when the keyboard weight is attached to the key, the hollow member is pressed from both sides in the length direction, whereby buckling occurs starting from the thin portion.