What are the finishing processes in sand casting?

Removing the excess material after the casting has solidified and cooled.

removing excess material

Once the casting has cooled and solidified it needs to be demoulded and undergo a process of removing all the runners, risers, and excess material before it undergoes additional treatments. These processes are grouped together under finishing. The excess material can often be re-used in future
castings - minimising waste and cost to support a circular economy.

GW_Sand Casting Process Map

Knock out

The casting needs to be removed from the mould. This can be done either by thermal knockout, or by using mechanical processes such as a rattler.

Bandsawing

This removes the runner system and feeders from the casting. It can also be robotised when the volume is justified.

Fettling

Fettling removes flash and other extraneous material not part of the final product. This can be done with hand tools for smaller volumes, or robots for production volumes.

Shot blast

Used to give the casting a more uniform appearance and remove any burrs. Further surface finish treatments are usually applied such as powder coating, painting, or machining.

Read more: Why are cores used in sand casting?

Read more: How can sand casting contribute to a carbon neutral future?

Read more: Find out more about the CNC machining and finishing in our ebook The Machining Buyer's Guide.

 

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