The gas would exist between the mold cavity and metal liquid

　　The main reason why the ESCO bucket tooth pin surface has the air hole is because there are some gas exist in the content of metal liquid, and ESCO bucket tooth pin production manufacturer attention that the exist position of these gas is between the mold cavity and metal liquid, during the whole mold filling period, because the metal liquid can’t dissolve all of these gas, so after the metal liquid connect with the gas, it would curdle into a thin shell, so the gas, which can’t been fully discharge out would connection on some position among the inside of the ESCO bucket tooth pin and form into the air holes.

　　The ESCO bucket tooth pin production manufacture also attention that because the working condition of the pressure casting process is under the high pressure to mold filling and curdle, so the gas, which exist in the surface of the metal liquid would compress with a very fast speed, it also create a condition to form into the air holes.