The crystallization characteristics and casting properties of copper alloys with different composition of brass bars are different, and the casting process characteristics are also different. 1. Tin bronze: The crystallization characteristics are large scale of crystallization temperature and wide condensation area. Casting properties are poor in mobility, easy to produce shrinkage, not easy to oxidize. The process features are directional condensation (sequential condensation) for wall thickness parts, simultaneous condensation for complex thin-walled parts and common wall thickness parts. 2. Aluminum bronze and aluminium brass: The crystallization characteristic is that the crystallization temperature scale is small and the crystallization characteristic is layer by layer. It is easy to form convergent shrinkage holes and oxidize because of its good mobility in casting properties. The technological characteristics are that the casting system of aluminium bronze is bottom casting type and the casting system of aluminium brass is open type. 3. Silicon brass: The crystalline characteristic is between tin bronze and aluminium bronze. Casting property is the best (in special brass). The process features sequential condensation process, medium pouring system and small size of dark riser.