What is "gong metal"

Gong \Gong\, n.

1. [Malayan (Jav.) g[=o]ng.] An instrument, first used in the East, made of an alloy of copper and tin, shaped like a disk with upturned rim, and producing, when struck, a harsh and resounding noise.

   O'er distant deserts sounds the Tartar gong.
   --Longfellow.

2. (Mach.) A flat saucerlike bell, rung by striking it with a small hammer which is connected with it by various mechanical devices; a stationary bell, used to sound calls or alarms; -- called also gong bell.

   Gong metal, an alloy (78 parts of copper, 22 of tin), from which Oriental gongs are made.