Cost Drivers for sand casting
Author: Date: 2015-12-1 14:51:24
Material cost
The material cost for sand casting includes the cost of the metal,melting the metal,the mold sand,and the core sand. The cost of the metal is determined by the weight of the part,calculated from part volume and material density,as well the unit price of the material. The melting cost will also be greater for a larger part weight and is influenced by the material,as some materials are more costly to melt. However,the melting cost in typically insignificant compared to the metal cost. The amount of mold sand that is used,and hence the cost,is also proportional to the weight of the part. Lastly,the cost of the core sand is determined by the quantity and size of the cores used to cast the part.
Production cost
The production cost includes a variety of operations used to cast the part,including core-making,mold-making,pouring,and cleaning. The cost of making the cores depends on the volume of the cores and the quantity used to cast the part. The cost of the mold-making is not greatly influenced by the part geometry when automated equipment is being used. However,the inclusion of cores will slightly slow the process and therefore increase the cost. Lastly,the cost of pouring the metal and cleaning the final casting are both driven by the weight of the part. It will take longer to pour and to clean a larger and heavier casting.
Tooling cost
The tooling cost has two main components - the pattern and the core-boxes. The pattern cost is primarily controlled by the size of the part (both the envelope and the projected area) as well as the part's complexity. The cost of the core-boxes first depends on their size,a result of the quantity and size of the cores that are used to cast the part. Much like the pattern,the complexity of the cores will affect the time to manufacture this part of the tooling (in addition to the core size),and hence the cost.
The quantity of parts that are cast will also impact the tooling cost. A larger production quantity will require the use of a tooling material,for both the pattern and core-boxes,that will not wear under the required number of cycles. The use or a stronger,more durable,tooling material will significantly increase the cost.