The steel titanium alloy customized by calss C Tongue drum from steel mills is different from fake steel titanium alloy with more iron (Fe) impurities on the market. The steel titanium content of the alloy customized by the new C series drum is based on the steel titanium content of Luru’s original high-end steel titanium model. The content is customized as a reference, the ratio is very stable, and the feature is that there is no "iron knocking" and it solves the problems of rust and intonation.