Bisheng normally use p20�738,2344 and 718 for the injection molds. which will make our products smooth and the mold will be antirust and the mold will have a longer life. For higher requirements we use S136�344,8407. the design of cooling system: the design of cooling system is a very complicated task, we need to consider the effect of the cooling system , at the same time we need to consider the size and location of the cooling system which will influence overall structure of the mold. Also we need to consider the cooling of the key parts such as Core inserts 、Slider and inserts of slider. We still will consider the design of the parts of cooling system and the selection of standard parts. we will analyse these questions when we design the mold, we apply circulating water system to make it flow in every part of the mold to reduce the time of cooling, and improving injection time and cutting your cost. The maintenance of mold: The maintenance is much more important than repair, repair will shorten the life span of the mold, so we say good maintenance will ensure the long life span of your mold. how we will maintain your mold: the daily maintenance: the oil maintenance of moving parts, such as: Ejection Pin、Slider、Guide Pin、Guide Bushes, the cleaning of the surface, the clearance or the water system, all of these are daily work.