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The Newby Foundries Group comprises of 4 companies providing our key services.
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t: 0044 (0) 121 556 4451

Iron casting process

Shell moulding
Vacuum casting
Air set moulding
Green sand casting

We are proud to be a leading UK shell foundry and iron casting manufacturer.


Newby utilise the latest metal casting techniques to produce high quality sand castings. Our large purpose built iron casting foundry specialises in both shell moulding and our unique vacuum backed shell moulding processes. These manufacturing methods in addition to airset and greensand moulding enable us to provide customers with the most suitable casting solution for many applications and quantities.


Find out more about the processes we offer below.


Shell moulding


Shell moulds are produced by pouring resin covered sand onto a heated iron pattern. The resin fuses together and cures to create a hard ‘biscuit’ shell.


Parts produced using the shell process achieve excellent reproduction of detail, a very good surface finish and CT9 tolerance for high dimensional accuracy which reduces machining requirements. Complex core assemblies are possible due to the strength of the cores.


The shell process at Newby Foundries is ISO/TS 16949 and ISO 9001 certified. Our plate size is 600 X 400mm and castings must fit within this size limit. We have two shell casting methods;



  • Shells are cast on a continuous loop track
  • Suitable for parts up to 25kg
  • Medium to high volume production


Vacuum backed

  • Vacuum backed shell moulding process is unique to Newby Foundries. Shells are embedded inside a sand filled flask under vacuum pressure.
  • The increased pressure allows parts up to 100kg to be cast at a high tolerance
  • Other advantages include minimal mould dilation and increased gas removal
  • Medium volume production

Airset moulding


  • Airset moulds are produced from wood or resin patterns mounted in frames.  Sand is mixed with catalyst and binder which causes a hardening reaction.  Before the sand cures it is rammed into the frames.  The resulting mould can then released from the frames and assembled.
  • Suitable for parts up to 150kg
  • Maximum mould size is 1.8m X 1.8m X 1.8m
  • A tolerance of CT11 can be achieved
  • Low to medium volume production

Greensand moulding


  • For basic, low cost iron castings
  • Up to 20kg approx
  • Low volume or batch production
  • CT12 tolerance


Would you like to discuss a project?
Contact us here today.