The body of the basic grade barrel is made of 45 # steel. The liner of the barrel is made of basic alpha-101 bimetallic material.

The high-grade barrel adopts imported HIP powder alloy oval liner. Its material has excellent wear resistance, corrosion resistance and other properties. It has won praise and praise from many users. It is incomparable with the conventional bimetallic structure "C" bushing widely used in the industry at present, and it is also incomparable with other types of steel after surface hardening treatment.