Two stages, two sets of acceptance rules
Mill supply is ordered to a product standard and its dimensional requirements. Cutting, leveling, bending and drilling create a second acceptance stage for the finished part. An order that says only “standard tolerances” can leave the buyer and processor measuring different things.
For a flat panel, mark the inspection face, support condition and measuring method. State whether flatness is assessed on the unrestrained sheet or after it is fixed to a subframe. For a cut blank, identify the datum and whether overall length, diagonal difference or edge squareness is important.
Put each tolerance next to the feature
| Feature | Possible acceptance detail |
|---|---|
| Thickness | Applicable base product standard and inspection point |
| Flatness | Face, support setup, span and measurement method |
| Outline | Finished width, length, corner and diagonal requirements |
| Cut edge | Burr, taper, roughness or finishing where relevant |
| Holes | Datum, size and position relative to mounting system |
Critical architectural fit or automated assembly may justify a first-piece approval before the entire order is processed. If the drawing uses unusually tight values, check fabrication feasibility and inspection cost before fixing a delivery date.
Keep the paperwork connected
- Quote the base material standard and finished-part drawing revision.
- Separate mill inspection records from part-dimensional records.
- Specify how nonconforming parts will be identified and reviewed.
- Agree packaging that preserves the accepted shape.
See the processing overview and cutting process guide. The agreed purchase order and drawing control the inspection method.
This guide is general buying information. The current material standard, project drawing and agreed purchase documents control technical acceptance and supply.