---
title: "Look up ISO 2768 general tolerance values for a given grade, nominal dimension, and tolerance type."
method: POST
path: "/tools/get_iso2768_tolerances"
---

# Look up ISO 2768 general tolerance values for a given grade, nominal dimension, and tolerance type.

`POST /tools/get_iso2768_tolerances`

## Request

- Base URL: `https://api.mechanofab.com/v1`
- URL: `https://api.mechanofab.com/v1/tools/get_iso2768_tolerances`
- Auth: HTTP bearer

Use when the user asks about ISO 2768 tolerances (e.g. 'what is ISO 2768-m tolerance for 50mm?', 'ISO 2768 fine grade flatness?', 'general tolerance for machined parts'). Returns the ±tolerance value, range string, and applicable dimension range.

## Request body

- object
  - `grade` 'f' | 'm' | 'c' | 'v', required: f=Fine, m=Medium, c=Coarse, v=Very Coarse
  - `nominal_dimension_mm` number, required
  - `tolerance_type` 'linear' | 'angular' | 'flatness' | 'straightness' | 'roundness', required

## Response `200`

Tool result

- object
  - `grade_description` string, required
  - `tolerance_value_mm` number, required
  - `tolerance_range_string` string, required
  - `applicable_dimension_range` string, required
  - `standard_reference` string, required
  - `source_tag` string, required

## Other responses

- `400`: Invalid request/input.
- `401`: Missing/invalid credentials.
- `402`: Insufficient credits.
- `403`: Scope/tool forbidden.
- `404`: Unknown resource.
- `409`: Idempotency conflict.
- `429`: Rate limited.
- `503`: Control plane / runtime unavailable.

---

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