Shaft/Axle: made of 45# steel or 50Mn steel, the raw steel is rough turned, go to the process of hardening and tempering, then heat treatment and rough polishing finally.

Shell/Body: made of 50Mn or 45Mn steel, the raw material is forged into semi-finished products, being rough turned, (harden and tempered for 1-year guarantee as the quality is better), surface of the body is heat treated to HRC52-58, then finish turning finally.

Side cover: made of nodular cast iron (some factories in Shandong use nodular cast steel, the quality of the product is better and price is more expensive). Rough and finish turning after casted, then drilling the holes.