EPTAHUB’s Manufacturing Standards

Metal Die Casting

• Standard mold machining tolerances are +/- .010", with an additional +/- .001" per inch to account for shrinkage.
• Tighter as-molded tolerances can be requested but may increase tooling costs. Many tight tolerance requirements require mold manufacturing, sampling, and refinement. EPTAHUB will machine critical features to a steel-safe condition.
• Critical toleranced features and surface finishes may require post-machining, which should be noted during the quoting phase prior to order placement. Post-machined features will adhere to EPTAHUB's CNC manufacturing standards.
• EPTAHUB produces die cast components based on the net-shape (as-cast) model provided by the customer. These models must include sufficient material allowance for any required post-processing, such as machining. We recommend providing both the as-cast 3D model and the final model with accompanying technical drawings.
• Part-to-part repeatability is typically within +/- .004".
• As-cast surface finish is generally 64 µin. The standard finish for die casting is as-cast, and specific Ra values cannot be guaranteed without additional processing.
• Lead time specified refers to the first article shipment (T1 shipment). Production time for remaining orders is confirmed after first article approval.
• Typical first article shipments include five pieces, though this may vary based on part size, origin, and material.
• All quotes assume designs include adequate draft angles, radii, and coring for optimal manufacturability.
• Core design, side actions, and tooling strategy are determined by EPTAHUB unless explicitly discussed and agreed upon with the customer.
• Gating, ejection points, knit lines, and parting lines are at EPTAHUB's discretion unless specified otherwise by the customer.
• Die cast parts will have visible parting lines, appearing as thin ridges across the part.
• Cast parts may have one or more gate vestiges, which are trimmed, sheared, or ground off during production.
• Ejector pin marks—resembling small round flats—will be present on die cast parts.

Plastic Material Extrusion

• All quotes assume designs include adequate wall thicknesses, radii, and feature sets optimized for the extrusion process.
• Critical-to-function tolerances should be discussed during the quoting phase to ensure tooling strategy, check gages (if applicable), and other quality controls are included in the quote.
• Critical toleranced features and surface finishes may require post-machining, which should be noted during the quoting phase prior to order placement. Post-machined features will adhere to EPTAHUB's CNC manufacturing standards for plastics.
• Customer-provided models must include sufficient material allowance for any required post-processing, such as machining. EPTAHUB recommends providing both the extruded 3D model and the final model with accompanying technical drawings.
• Wall thickness tolerance is typically +/- 10% of the specified dimension.
• Angularity tolerance is typically +/- 3 degrees for rigid materials and +/- 5 degrees for flexible materials.
• Typical twist tolerance is not to exceed 0.5 degrees per 12" of length. Camber and bow tolerances are not to exceed .025" per 12" of length.
• Plastic extrusion surface roughness will be 125 µin Ra or better.
• Sharp corners will have a minimum radius of .016".
• Extruded tubes are limited to four lumens unless otherwise agreed upon.
• Internal dimensions of hollow features are difficult to control and require tolerances significantly larger than standard values.

Standard Plastic Extrusion Tolerances By Feature Size

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