Mastering Plastic Molding Precision: The Definitive Guide to the ISO 20457 Tolerance Table
The tolerances vary depending on the material, as different plastics shrink and mold differently. The standard generally divides materials into groups:
The standard distinguishes between two fundamental types of dimensions based on their relationship to the mold: iso 20457 tolerance table pdf
: For a more visual breakdown of the material categories and tolerance groups, Online Documentation on understanding plastic part tolerances. OKW Gehäusesysteme TOLERANCES
A practical summary of the TG6 group values used for injection molding is available through technical resources like OKW Tolerances ISO Official Standard: The full official text and thumbnails for ISO 20457:2018 are available on the ISO Online Browsing Platform Templates & Snippets: Mastering Plastic Molding Precision: The Definitive Guide to
| Nominal Outside Diameter ($d_n$) (mm) | Tolerance (mm) | | :--- | :--- | | $d_n \le 16$ | +0.3 / 0 | | $16 < d_n \le 63$ | +0.4 / 0 | | $63 < d_n \le 110$ | +0.5 / 0 | | $110 < d_n \le 160$ | +0.6 / 0 | | $160 < d_n \le 225$ | +0.7 / 0 | | ... | ... |
TG6 is widely used for standard thermoplastic parts in applications such as packaging and general consumer goods. Many commercial manufacturers specify ISO 20457 TG6 as their default general tolerance for thermoplastics. (and its German equivalent DIN ISO 20457 )
(and its German equivalent DIN ISO 20457 ) is the primary international standard for specifying manufacturing tolerances of plastic molded parts
Note: This table is a representative summary. The official ISO 20457 PDF contains exact values and footnotes regarding chamfers, radii, and external/internal dimensions.
The standard provides tolerance tables categorized by the and the Material Group .
Note: The format +X / 0 indicates that the pipe can be larger than nominal by X mm, but cannot be smaller than the nominal size (ensuring it can seal).