pantaz said:Bore diameter will decrease.
Ritz_physics said:So this is exactly what would happen during the cooling of a similar casting, after it has solidified?
Wikipedia said:... Some alloys will have overall linear shrinkage of up to 2.5%, whereas other alloys may actually experience no shrinkage or a slight "positive" shrinkage or increase in size in the casting process (notably type metal and certain cast irons). ...
http://en.wikipedia.org/wiki/Pattern_(casting)#Contraction_allowances_.2F_Shrinkage_allowance
Ritz_physics said:Ok.. anyway for most metals (the ones that contract on cooling) the bore diameter will decrease during the shrinkage of casting, right?
Shrinkage allowance for patterns is the amount of material added to a pattern to account for the shrinkage that occurs during the manufacturing process. This ensures that the final product is the correct size.
Shrinkage allowance is important because it ensures that the final product is the correct size and meets the desired specifications. Without it, the product may end up being too small after the shrinkage occurs.
Shrinkage allowance is calculated by multiplying the linear shrinkage rate by the dimensions of the pattern. The linear shrinkage rate is typically provided by the manufacturer or can be determined through testing.
The type of material, the manufacturing process, and the environment in which the product is produced can all affect the amount of shrinkage that occurs. It is important to consider these factors when determining the appropriate shrinkage allowance for a pattern.
Yes, shrinkage allowance can be adjusted based on the specific needs and requirements of the product. However, it is important to carefully consider and test any adjustments to ensure the final product meets the desired specifications.