Tolerances of Machined and Sheet Metal Parts

Xometry's Manufacturing Partner Network makes thousands of machines available to make your part at the click of a mouse. Since the minimum requirement to machine a part is a solid CAD file, we offer these general tolerances and guidelines (also found in our Manufacturing Standards). As always, we have free online Design Guides to go more in-depth on our manufacturing services.

CNC/Machining

  • +.005”/-.005” local tolerances across most geometries in metals, +/- 0.010" for plastics.  Will vary for large parts, specifically when holding flatness over large parts after heat treatment. 
  • Finish requirements for “As Milled” finish will have a minimum 125 surface finish for CNC parts.
  • All fabricated parts have a 0.010” dimensional and 1° angular tolerance.
  • Tapped holes not explicitly called out as Features on the quoted CAD model may be machined to the diameters specified in that model.
  • No surface treatments (e.g. anodize, bead blast, iridite, powder coat, etc.) will be applied unless you have paid for them and we have specifically acknowledged them.

Sheet Metal

  • +/- 0.010” – 0.020” is typical and highly dependent on geometric features like bends and weldments.
  • Xometry recommends staying above 14 gauge for best performance and designing with common gauge thickness.

As a general rule, please make sure all metal CNC parts have a minimum wall thickness of 0.030". For plastics, the minimum wall thickness should be at least 0.060". If our team finds a manufacturability issue we may put the project ON HOLD and reach out for some clarification or a design change.

Xometry's instant quoting platform allows you to specify even tighter tolerances as well as custom features. If you have any questions on your project, please contact support@xometry.com.

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