Our Manufacturing Standards

Updated December 9, 2021

CNC Machining and Turning

• For features of size (Length, width, height, diameter) and location (position, concentricity, symmetry) +/- 0.005” (metals) or +/- 0.010 (plastics and composites) in accordance with ISO 2768 unless otherwise specified.
• As machined surface finish is 125 Ra or better. Machine tool marks may leave a swirl-like pattern.
• Sharp edges will be broken and deburred by default. Critical edges that must be left sharp should be noted and specified on a print.
• Clear or transparent plastics will be matte or have translucent swirl marks on any machined face. Bead blasting will leave a frosted finish on clear plastics.
• For features of orientation (parallelism and perpendicularity) and form (cylindrical, flatness, circularity, and straightness) per the table below unless we have agreed to other tolerances in your Quote.

Plastic Injection Molding

• Typical mold machined tolerances are +/- 0.005″ when machining the mold and an additional +/- 0.002″ per in. when calculating for shrink rate.
• Tighter tolerances can be requested and may increase the cost of tooling. Additionally, many tight tolerances require the mold to be manufactured, sampled, and then groomed. Xometry will mill to a steel-safe condition on critical features.
  Part-to-part repeatability is typically under +/- 0.004″.
• Lead time stated is for first article shipment. Remaining production time is confirmed after first article approval.
• Typical first article shipments are 10 pieces but may vary based on size, origin, and material.
• Xometry cannot guarantee a perfect color match per Pantone color.
• All quotes are based upon the assumption that designs have an adequate draft, radii, and coring for manufacturability.
• Cores, side actions, and tooling strategy are determined by Xometry unless explicitly discussed.
• Gating, ejection, knit lines and parting lines are at the discretion of Xometry unless explicitly discussed.

Sheet Cutting Service

• Thickness tolerances are independent of cutting tolerances, as they rely on the raw stock material’s tolerance range.
• Edge to edge tolerances is +/- 0.005” nominal on the top face of the plate/sheet.
• Thicker materials may have a tolerance deviation on the bottom face due to tapers inherent in laser cutting, waterjet cutting, or plasma cutting.
• Xometry cannot guarantee flatness call outs for sheet cut materials.
• Holes of 0.100” or smaller in diameter may be slightly larger than standard tolerances due to material pierce happening near the hole’s profile.
• A small bump of material or a different edge condition may be present at the lead-in and lead-out in a cutting profile.
• Tabs may be present on parts under two inches to hold the workpiece during manufacturing using waterjet or fiber laser machines.
• Pre-finished or textured sheets, such as brushed or polished stock may have only one side with the cosmetic finish.
• Protective film may be shipped on cut products to prevent damage of cosmetic finishes.
• The edge condition of sheet cut materials will have vertical striations versus smooth edges. This affects the transparency of edges on clear plastics.
• Large burrs and tabs will be removed, but parts are not manually fully deburred before shipment unless explicitly requested or an advanced finish, such as chem films or coatings, is requested.
• Some cut materials may show a small halo discoloration from backsplash or overspray near the cut edges.

Sheet Metal Fabrication

• Forming and bending: +/- 0.020″
• Bend to hole or feature: +/- 0.010″
• Linear dimensions excluding locations to bends: +/- 0.005″
• Angularity: +/- 2 degrees
• Surface roughness (blank material): Ra 125 uin max
• Surface roughness (timesave): Ra 100 uin max
• Sharp edges will be broken and deburred by default. Critical edges that must be left sharp should be noted and specified on a print.
• Certain sheet metal designs require custom tooling and will be flagged for a manual quote: hems, curled flanges and rolled sheets, stamped parts, and welded assemblies. If your part includes these features, please allow our manual quote team to review and provide you with an accurate cost and lead time.

Urethane Casting

• Tolearance are +/- 0.010” or +/- 0.003” per inch, whichever is larger, is typical. Irregular or overly-thick geometries may cause deviances or deflection due to shrinkage.
• A shrinkage rate of +0.15% can be expected due to thermal expansion of the liquid, and the response of the flexible mold.
• Surface finish is externally smoothed to a satin or matte surface. Grow lines may be present on internal or difficult-to-access features. Polishing or custom finishes must be clearly defined and agreed upon at the point of order.
• Sharp corners and text may appear slightly rounded.

Metal Binder Jetting 3D Printing

• Metal binder jet parts are made in ExOne 420i metal, which is roughly 60% 420 stainless steel and 40% bronze infiltration.
• Depending on the part’s size and geometry, parts may shrink 0.8% – 2.5% after processing.
• Internal geometries, such as slots and holes, may shrink as much as 5%.
• Xometry does not guarantee tolerances on the first attempt at a new design.
• Improved tolerances may be possible with a manual quote review, after successful completion of a prototype build, and must be approved on a case-by-case basis.
• Metal binder jet machines print in layers of 0.004” (0.1 mm) and parts are typically oriented in the lowest Z direction.
• Parts with features below 0.03” (0.75 mm) will need to be thickened for successful processing. It is recommended the minimum feature size be above 0.04″ (1 mm).
• Modeled threads or precision features may have limited functionality as printed.
  Tumble polished parts may have trapped walnut media between thin gaps or text features.

Carbon DLS™ 3D Printing

• +/- 0.005” for the first inch is typical, plus +/- 0.002” for every inch thereafter. However, Xometry does not guarantee tolerances on the first attempt of a new design. Tolerance expectations can vary across different materials (e.g. elastomeric versus rigid materials).
• Stresses during build, support strategy, and other geometry considerations may cause deviation in tolerances and flatness.
• Parts with thicker geometries, flat or broad parts, and parts with uneven wall thicknesses may be prone to significant deviations or warp.
• Modeled threads or precision features may have limited functionality as printed. Tapping or the addition of threaded inserts is recommended for best function.
• Improved tolerances may be possible with a manual quote review, after successful completion of a prototype build, and must be approved on a case-by-case basis.

DMLS 3D Printing

• +/- 0.005” for the first inch is typical, plus +/- 0.002” for every inch thereafter. However, Xometry does not guarantee tolerances on the first attempt of a new design. Tolerance expectations can vary across different materials (e.g. stainless steel versus aluminum).
• Internal stresses during build, support strategy, and other geometry considerations may cause deviation in tolerances and flatness.
• Items and geometries which require strict flatness are not a good fit for this process.
• Modeled threads or precision features may have limited functionality as printed. Tapping or the addition of threaded inserts is recommended for best function.
• Expected surface roughness is 150-400 µin RA, depending on build orientation and material used for the build.

FDM 3D Printing

• +/- a single build layer thickness for the first inch and +/- .002” for every inch thereafter.
• 0.010” layer thickness is used for parts fitting within a 14” X 16” footprint (Fortus 450)
• 0.013” layer thickness is used for parts exceeding 14” X 16” footprint (Fortus 900)
• 0.008″ layer thickness used for Prototyping PLA (9.8″ x 8.2″ x 8.2″, Prusa MK3S desktop FFF)
• Guaranteed tolerances may be possible with a manual quote review, and must be approved on a case-by-case basis.
• Xometry chooses optimal build orientation taking into consideration overall surface quality and minimum build time unless otherwise specified.
• Minimum resolvable feature size, including positive text features, is at least 0.035” (0.045” or greater is safest).
• Modeled threads or precision features may have limited functionality as printed. Tapping or the addition of threaded inserts is recommended for best function.
• Horizontal holes and protrusions will build slightly oblong due to stair stepping from layers.
• Nylon 12, ULTEM 9085, and ULTEM 1010 parts with thicker geometries, flat or broad parts, and parts with uneven wall thicknesses will be prone to significant deviations or warp due to variable thermal shrinkage and stress.

HP MJF 3D Printing

• +/- 0.012” up to 4″ is typical, plus +/- 0.003” for every inch thereafter.
• Parts with thicker geometries, flat or broad parts (>7”), and parts with uneven wall thicknesses will be prone to significant deviations or warp due to variable thermal shrinkage and stress.
• Modeled threads or precision features may have limited functionality as printed. Tapping or the addition of threaded inserts is recommended for best function.
• Natural grey color may be inconsistent depending on feature size and build orientation. Dyed black is recommended for production parts.
  Guaranteed tolerances may be possible with a manual quote review, and must be approved on a case-by-case basis.

Polyjet 3D Printing

• +/- 0.004” for the first inch is typical, plus +/- 0.002” for every inch thereafter.
• Minimum feature size of 0.050” can be built with consistency.
• Rubber-like materials represent an approximation of shore A values and may vary between geometries.

SLA 3D Printing

• Guaranteed tolerances may be possible with a manual quote review, and must be approved on a case-by-case basis.
• Modeled threads or precision features may have limited functionality as printed. Tapping or the addition of threaded inserts is recommended for best function.
• Tolerances for Standard and High Resolution options are described in the table below

SLS 3D Printing

• XY Planes: +/- 0.005” for the first inch is typical, plus +/- 0.002” for every inch thereafter.
• Z Direction: +/- 0.010” for the first inch is typical, plus +/- 0.002” for every inch thereafter.
• Parts with thicker geometries, flat or broad parts (>7”), and parts with uneven wall thicknesses will be prone to significant deviations or warp due to variable thermal shrinkage and stress.
• Modeled threads or precision features may have limited functionality as printed. Tapping or the addition of threaded inserts is recommended for best function.
• Guaranteed tolerances may be possible with a manual quote review, and must be approved on a case-by-case basis.

General Manufacturing: Mating and Flexible Features

• Xometry is not responsible for the fit of mating parts.
• Xometry is not responsible for the function of snap tabs, clips, or living hinges.