Sand Casting

Cost Effective Metal Fabrication

Sand Casting Process Overview

Sand Casting is the process of pouring molten metal into a mold constructed of densely packed sand, letting it fill a custom designed void in that mold, allowing it to cool, and then removing the solidified part from the mold by cracking the mold open.  Sand Casting is commonly used for larger parts like automotive manifolds or industrial brackets.  Sometimes, it is appropriate to 3D Print the mold using a sand binder jetting printer.

Also Known As

  • Sand Casting
  • Waste Casting

Process At A Glance

Common Materials

Iron, Steel, Aluminum, Titanium

Standard Tolerance

+/-.03" to +/- 3% depending on part size

Stock Surface Finish

~600 µin Ra

Lead Time

15-25 Business Days

Maximum Size

71" x 39" x 27" (1800mm x 990mm x 685mm)

Minimum Layer Thickness

n/a

Minimum Feature Size

0.3" (7.5mm) - Sand Casting

Minimum Wall Thickness

0.04" (1mm) dependent upon material

sand casting

Advantages

  • Reasonably Priced Bulky Parts - Because material is poured into the mold rather than printed using powder, it is much faster to fabricate bulky parts and with that, less expensive
  • Fast Turn - While tooling for heavy duty investment casting can take months, sand castings can typically be fabricated in a matter of weeks - especially 3D Printed sand molds

Limitations

  • Sand Casting not viable for onesy-twosy projects - While complex sand molds and cores can be made more affordably than ever via 3D Printing, foundries generally aren't interested in one-off casting projects
  • Surface Finish is Imprecise - Standard finish out of a casting - especially a sand casting - is quite rough.  Post processing is commonly needed, and extremely tight tolerances challenging to achieve due to shrinkage of the metal during the cooling and re-solidification process   
  • Strength/Durability - Castings are not as strong wrought metal parts and sometimes weaker than 3D Printed parts.  That being said, they are still metal and are quite durable as compared to many other material-process combinations

Example Machines

  • Custom Sand Molds
  • Custom Silica Molds

Example Materials

  • Iron
  • Steel
  • Aluminum
  • Titanium