Selection of aluminum casting method low pressure casting or sand casting?
Our customer had initially chosen sand casting as the production method for their production of manhole covers as the volume was not very high. When you have a small volume at the start of a production then the advantage of sand casting is a relatively low investment in moulds, but then on the other hand, one must accept that tolerances and finishes are not top quality, as well as that topic price is at the high end.
– As the volume of the manhole covers increased from level 300 to 600 per unit yearly it turned out that a change of production could pay off if they chose low-pressure casting as a production method. With investment in a low-pressure mould made of steel is the advantage that the items have better tolerances and higher finis as well as a lower item price – the investment in the new low-pressure mould was earned home the first year! And our customer got a significantly better quality on their manhole covers at a significantly cheaper price.
Sand casting aluminum is typically chosen for a small volume of approximately 10-300 pieces. The advantages of sand casting are that it is cheaper to get started. Sand casting is therefore also good for prototypes and test series.
Low pressure casting aluminum is suitable for cast series from 100-500 pcs. The advantage is that the low pressure casting have a better tolerances and a higher finish, as well as a low piece per pcs.