# Item Sets and Attribute Tolerances

All nine machined parts are in one item class, `CoreForge\WIP\Machined`, but they belong to three families with different specs. An **item set** groups items when the item classes don't match the grouping you need. Each item can belong to only one item set.

:::action[Create the item sets]

1. Navigate to **Configuration → Ops → Materials** and confirm `CoreForge\WIP\Machined` contains `CP-`, `PR-` and `SC-` items in 2024, 6061 and 7075. If not, import <a href="/files/quality-resources/items-coreforge-wip-machined.json" download><code>items-coreforge-wip-machined.json</code></a>.
2. Navigate to **Configuration → Quality → Item Sets** and open the item set editor.
3. Create three enabled item sets: `Coupling Pins`, `Precision Rods` and `Shaft Cores`.
4. Link `CP-2024`, `CP-6061` and `CP-7075` to `Coupling Pins`, the `PR-` items to `Precision Rods`, and the `SC-` items to `Shaft Cores`.

:::

::embed-section{src="../../../kanoa-quality/itemSets.md" collapsed="true" summary="Reference Materials: Item Sets"}

An **attribute** is a named quality variable, such as a diameter, that check items can refer to. Its tolerances can be set per asset, item, item set, or for all items, so the check item doesn't need a hard-coded spec.

:::action[Create the FAI Diameter attribute]

1. Navigate to **Configuration → Quality → Attributes** and create the folders `CoreForge` and `Machining`, then an attribute `FAI Diameter` inside them.
2. On its **Tolerance** tab, add one tolerance for each item set (all values in mm):

   | Item set | LEL | LSL | LCL | Target | UCL | USL | UEL |
   |---|---|---|---|---|---|---|---|
   | `Coupling Pins` | 9.85 | 9.90 | 9.95 | 10.00 | 10.05 | 10.10 | 10.15 |
   | `Precision Rods` | 14.80 | 14.88 | 14.94 | 15.00 | 15.06 | 15.12 | 15.20 |
   | `Shaft Cores` | 24.70 | 24.82 | 24.91 | 25.00 | 25.09 | 25.18 | 25.30 |

3. Make sure each tolerance is enabled, and save.

:::

A value between the control and spec limits passes but is highlighted as a warning. A value outside the spec limits (LSL/USL) fails. A value outside the entry limits (LEL/UEL) can't be entered.

::embed-section{src="../../../kanoa-quality/attributes.md#tolerances" collapsed="true" summary="Reference Materials: Attribute Tolerances"}