Iso 20457 Tolerance Table Pdf Jun 2026

It establishes realistic dimensional tolerances based on material properties. It defines acceptance conditions for quality control.

Tolerances that are too strict (e.g., trying to achieve TG3 on a complex, amorphous plastic part) can dramatically increase manufacturing costs by requiring more precise, expensive tooling and longer cycle times.

: These range from high precision (TG1) to normal production (TG9). For standard thermoplastics in injection molding, is a frequently used baseline for general tolerances. Dimensional Categories

For engineers, quality managers, and procurement professionals working with injection-molded plastic parts, precision is everything. However, the properties of plastics—from material shrinkage to thermal expansion—make them fundamentally different from machined metals. Applying metal tolerances to plastic parts inevitably leads to costly rework, rejected shipments, and strained supplier relationships. This is where comes into play. iso 20457 tolerance table pdf

Yes — but not a fixed one.

Choosing the right tolerance grade is a balance between functional requirements and manufacturing cost.

ISO 20457 has become the global benchmark for tolerancing injection-molded plastic parts. By adopting this standard, designers and engineers can move away from guesswork and ambiguous specifications. : These range from high precision (TG1) to

The is more than a grid of numbers; it is a strategic tool for balancing cost and quality. By understanding the three tolerance classes (Fine, Medium, Coarse) and knowing how to navigate the linear and angular tables, you can produce drawings that are both professional and manufacturable.

General tolerances used when dimensional requirements are not the primary quality focus. Series 2 (Accurate Production):

You can download the ISO 20457 tolerance table PDF from various sources, including: including: The machinist reads the PDF

The machinist reads the PDF, applies the correct deviations, and the bracket is cheap to produce (not over-toleranced) but still fits the motor.

While the full PDF requires purchase, several engineering portals (including ResearchGate, Academia.edu, and injection moulding forums) offer summary tables. These are useful for initial design but should never replace the official document for production contracts. A quick Google search for may lead to draft versions or manufacturer-specific adaptations – verify the revision date (2020) and table numbers before use.

For manufacturing engineers, purchasing the official ISO 20457:2018 PDF from your national standards body is an essential investment. The standard belongs on every plastics engineer’s reference shelf alongside ISO 2768 (for machined components) and ISO 22081 (for surface profile tolerancing).