Plastic Extrusion

• All quotes are based upon the assumption that designs have adequate wall thicknesses, radii, and feature sets designed for manufacturability in this process.
• Critical-to-function tolerances should be discussed at the time of quoting to ensure that tooling strategy, check gages (if applicable), and other quality controls are encompassed in the quote.
• Critical toleranced features and surface finishes may require post-machining and should be noted in the quote before ordering. Post-machined features will follow Xometry’s CNC manufacturing standards for plastics.
• Customer-provided models must contain appropriate material for additional post-processing efforts, such as post-machining. Xometry recommends providing the extruded 3D and final models with any accompanying technical drawings.
• Wall thickness is typically +/- 10% of the specified dimension.
• Angularity is typically +/- 3 degrees for rigid materials and +/- 5 degrees for flexible materials.
• Twist typically does not to exceed 0.5 degrees per 12” length. Camber and bow not to exceed .025” per 12” length.
• The surface roughness of plastic extrusions will be 125 μin Ra or better.
• Sharp corners will have a radius of at least .016”.
• Lumens within extruded tubes will be limited to four unless otherwise agreed upon.
• Dimensions inside of hollows are difficult to control and will require tolerances considerably greater than the standard tolerances.

Standard Plastic Extrusion Tolerances By Feature Size

* General tolerances strongly depend on the material extruded and cross-section complexity. Specialized tooling can be used to obtain tighter tolerances than those listed above.