Manufacturing Standards

Workmanship Standards

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) following 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.
• elimold cannot guarantee tolerances on foam or similar compressible materials.
• General tolerances for orientation and form features are outlined below unless we have agreed to other tolerances in your Quote. These features include parallelism, perpendicularity, cylindricity, flatness, circularity, and straightness.

CNC Orientation and Form General Tolerances

Die Casting

• Typical mold machined tolerances are +/- 0.010″ when machining the mold and an additional +/- 0.001″ per in. when calculating shrink rate.
• Tighter as-molded tolerances can be requested and may increase the cost of tooling. Additionally, many tight tolerances require the mold to be manufactured, sampled, and groomed. elimold will mill to a steel-safe condition on critical features.
• Critical toleranced features and surface finishes may require post-machining and should be noted in the quote prior to order. Post-machined features will follow elimold’s CNC manufacturing standards.
• elimold will produce die cast components according to the net-shape (as-cast) model provided by the customer. These models must contain appropriate material for any additional post-processing efforts, such as post-machining. It is recommended to provide the as-cast 3D model as well as the final model with any accompanying technical drawings.
• Part-to-part repeatability is typically under +/- 0.004″.
• As-cast surface finish is typically 64 μin. The standard finish for die-casting is as-cast and cannot guarantee a specific Ra value without additional processing.
• The lead time is for the first article shipment (T1 shipment). The remaining production time is confirmed after the first article approval.
• Typical first article shipments are five pieces but may vary based on size, origin, and material.
• 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 elimold unless explicitly discussed.
• Gating, ejection, knit lines, and parting lines are at the discretion of elimold unless explicitly discussed.
• Parting line(s) on die cast parts will be visible as a thin ridge traveling across the part.
• Cast parts may have one or many gate vestiges, which are trimmed, sheared, or ground off.
• Ejector pin marks will be present on die cast parts, resembling round flats.

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 groomed. elimold 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.
• Elimold 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 elimold unless explicitly discussed.
• Gating, ejection, knit lines and parting lines are at the discretion of elimold unless explicitly discussed.

Metal 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.
• Linear cross-section dimensions are +/- 0.010″, or +/- 0.006” per inch, whichever is greater, excluding wall thickness.
• Wall thickness is +/- 10% of the specified dimension.
• Cross-section angularity for external corners is +/- 1 degree, and +/- 2 degrees for internal angles.
• Critical toleranced features and surface finishes may require post-machining and should be noted in the quote before order. Post-machined features will follow elimold’s CNC manufacturing standards.
• Customer-provided models must contain appropriate material for additional post-processing efforts, such as post-machining. elimold recommends providing the extruded 3D and final models with any accompanying technical drawings.
• The surface roughness of as-extruded features is 125 μin Ra.
• Twist not to exceed 0.5 degrees per 12” length is typical.
• Straightness not to exceed 0.0125” per 12” length.
• Sharp corners will have a radius of at least 0.016”.
• Corner radii up to 0.188” will have a +/- 0.016” standard tolerance. Any radii over 0.188” will have a +/- 10% tolerance.

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 +/- 0.010” 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.
• elimold 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: +/- 0.010″
• 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.
• Specific 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.

Sheet Metal Tolerances Continued

Flat Parts

Sheet metal parts that utilize stock material gauge thicknesses and require no bending or milled features. All flat sheet metal parts can meet a +/-0.010” tolerance.

Simple Bend / One Surface

When designing parts with some type of bend with a standard bend radius, sheet metal tolerances are required to open. For simple bent parts, Xometry can offer a +/- 0.010” tolerance for dimensions across a single bend. The bend radius itself is constrained to a +/- 1.0°.

Multiple Surface Bends

For dimensions measured over multiple bends, Xometry can offer a +/- 0.030.

Metal Stamping

• All quotes are based upon the assumption that designs have an adequate draft, radii, relief cuts, and feature sets 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.
• Raw material such as coiled strip is not flat by nature and can show through on flat stamped or coined components.
• Dimensions apply to the inside of the formed feature.
• Angular tolerances of +/- 1 degree are typical.
• Stamped parts will be free of splits and other forming defects.
• Punch and die-cut features, such as edges, will have a straight wall with a small burr on the bottom edge approximately ¼ to ⅓ down the wall thickness.
• Large burrs and tabs will be removed, but parts are not manually fully deburred before shipment with a standard, as-cut finish selection.
• Linear dimensions for internal holes will be measured at the shear, or smallest portion of a cut feature.
• Tooling marks are a normal part of the metal forming process. Marks can be minimized with secondary processing or tooling strategy. It is important to identify cosmetic features with Xometry during the quoting or kick-off phase.
• The material thickness will vary across formed and drawn features.
• Part-to-part repeatability is typically under +/- 0.004″ (+/- 0.002” typical).

Laser Tube Cutting

• Thickness tolerances are independent of cutting tolerances, as they rely on the raw stock material’s tolerance range.
• Edge-to-edge tolerances are +/- 0.010” nominal on the outer face of the tube.
• Thicker materials may have a tolerance deviation on the bottom face due to tapers inherent in laser cutting.
• 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.
• A protective film may be shipped on cut products to prevent damage to cosmetic finishes.
• Large burrs and tabs will be removed, but parts are not manually fully deburred before shipment with a standard, as-cut finish selection.
• Some cut materials may show a small halo discoloration from the backsplash or overspray near the cut edges.

Tube Bending

• Tube bending manufacturing standards reflect draw or mandrel bending techniques. Compression bending, roll bending, or other bending methods will require functional specifications agreed upon at the time of order.
• Thickness tolerances are independent of cutting tolerances, as they rely on the raw stock material’s tolerance range. Tolerance measurements will assume a maximum material condition of the stock.
• Overall tube sheath envelope tolerance is +/- 0.125” typical.
• Tolerances are cumulative across bent tube feature.
• Linear dimensions excluding locations to bends: +/- 0.010″.
• Simple bend, planar, +/- 0.010”.
• Multiple surface bends, multi-planar, +/- 0.030”.
• Angularity: +/- 2 degrees.
• Tube end diameter tolerancing is +/- 0.020”.
• Ovality at a tube bend should not exceed 10% (5% to 8% typical) of averaged measured OD vs.. nominal OD. The equation for ovality is ((Max Ø – Min Ø) ÷ specified Ø) x 100.
• Thicker materials may have a tolerance deviation on the bottom face due to tapers inherent in cutting.
• Holes of 0.100” or smaller diameter may be slightly larger than standard tolerances due to material 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.
• A protective film may be shipped on cut products to prevent damage to cosmetic finishes.
• Large burrs and tabs will be removed, but parts are not manually fully deburred before shipment with a standard, as-cut finish selection.
• Some cut materials may show a small halo discoloration from the backsplash or overspray near the cut edges.

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 order of 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.
• General tolerances apply before secondary finishing or post-processing unless otherwise specified.

Carbon DLS™ 3D Printing

• +/- 0.005” for the first inch is typical, plus +/- 0.002” for every inch thereafter. However, elimold does not guarantee tolerances on the first order 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.
• General tolerances apply before secondary finishing or post-processing unless otherwise specified.
• Areas with support structure may show raised bumps where the structure was removed. In certain materials, like EPX, SIL, and EPU, supported areas may be more visible because post-processing options are limited.

DMLS 3D Printing

• +/- 0.005” for the first inch is typical, plus +/- 0.002” for every inch thereafter. However, elimold does not guarantee tolerances on the first order 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.
• General tolerances apply before secondary finishing or post-processing unless otherwise specified.

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.
• elimold 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.
• General tolerances apply before secondary finishing or post-processing unless otherwise specified.

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.
• General tolerances apply before secondary finishing or post-processing unless otherwise specified.

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.
• General tolerances apply before secondary finishing or post-processing unless otherwise specified.

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
  General tolerances apply before secondary finishing or post-processing unless otherwise specified.

SLS 3D Printing

• +/- 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 tolerances apply before secondary finishing or post-processing unless otherwise specified.