For a gasket, technical felt, sealing part or any cut piece that seats on a machine, the sample is not cut to “look right” — it is cut to fit. A good sample brief collects the material, the critical dimensions, the use case and the test method on one page. This guide shows how to write that page.

An industrial sample is not a packaging sample

A box sample can be judged by eye; an industrial part is judged by whether it seats on a flange, in a channel or on a housing. Hole-centre distances, axis offsets and thickness direction are functional values: a 0.3 mm deviation is invisible to the eye and still cancels the part at assembly.

That is why the first sentence of an industrial brief defines the part’s job: “This gasket seats on the cover flange of pump X; the sealing surface is the inner ring.”

  • An industrial sample is verified by assembly, not by eye.
  • Hole centres and axis dimensions are functional tolerances.
  • The brief’s first sentence states where the part will seat.

The core of the brief: material, critical dimensions, tolerance split

The material line carries type, thickness and hardness together: “3 mm NBR gasket sheet, Shore 65.” Flexible materials — rubber, felt, foam — change behaviour under the knife; the same rule gives a different result at a different hardness.

Dimensions are split in two: the critical ones (hole diameter, centre-to-centre distance, outer contour) are written with their tolerance — for example “centres 120 ±0.2 mm” — and the rest are left free. Putting a tolerance on every dimension is as misleading as putting one on none.

  • The material line gives type + thickness + hardness (Shore) together.
  • Critical dimensions are marked individually with their tolerances.
  • The reference edge or reference hole is identified on the drawing.

Write the test expectation and sample quantity up front

The brief states how the sample will be tested: a dimensional check only, or a trial on the real assembly? If an assembly test is planned, the sample must be cut from the production material itself — an assembly result from a “similar” material proves nothing.

Sample quantity follows the test type: 1–2 pieces cover a dimensional check, while a compression or sealing trial reasonably needs 5–10 pieces.

  • The test type (dimensional / assembly / sealing) is written explicitly.
  • Assembly tests require samples cut from the real production material.
  • The sample quantity is set up front to match the test type.

After the sample: the approval record carries the production run

The test result is recorded in writing with photos: which dimensions passed, where a revision is needed. If there is a revision, a new drawing opens under a new file name; the approved sample’s file is marked as the approved revision and the production run is made only from that file.

The record protects both sides: the reorder six months later starts not with “which dimension was it?” but with “continue from approved R2”.

  • Test results are recorded dimension by dimension, with photos.
  • The approved file is flagged; production runs only from it.
  • Reorders are opened against the approved revision number.

Quote details we clarify together

When the file, material, quantity and deadline are clear, the quote conversation moves faster and with less back-and-forth.

  • Current revision file
  • Material and quantity details
  • Critical dimensions or production notes
  • Deadline expectation and delivery preference