Why must my fixture absorb the FR5 mounting-plate substitution?

Yes. She has both drawings, but the seller has not identified the supplied plate drawing.

Then equivalent is a sales answer with the useful page missing. Ask for the supplied drawing and have your designer mark the conflict. Don't pay her to redesign around a photograph.

ZaraBrown, I agree about asking, though the supplied plate may turn out to suit after a proper comparison. Anna needs to know whether the locating shoulder changes the seated position, and whether the complete tool assembly still matches what her integrator assessed.

Could Anna send one marked comparison with the original acceptance attached, so the seller has a specific mismatch to answer rather than another general request for clarification?

Yes, Dinesh. Put the supplied reference in the subject once they identify it. Otherwise each reply seems to acquire a fresh plate (we had that happen with a camera bracket).

I would not change the spare list yet. Keep the delivered reference marked as unaccepted stock. Otherwise someone can reorder it while this discussion is still going on.

Victor, that happened in our stores with an unconfirmed adapter. It was entered as the new version and the next request copied it. AnnaBaker's separate stock status would have saved us a second argument.

Supplied drawing received. Our designer found that the shoulder prevents our tooling seating. I have requested the agreed plate, with her marked section attached. Thank you, Dinesh; that single comparison finally got an answer.

Does the reply actually offer that plate, Anna? I would keep the existing tooling arrangement as the starting point unless your integration team chooses a change. A new adapter could bring another set of dimensions into this.

They offered a spacer first. I declined it. They now offer the agreed plate and collection of the substitute, with no extra charge in their written proposal.

Good. A spacer isn't automatically a harmless concession. Your designer shouldn't have to carry a new tool offset and fixing arrangement just to make their substitution disappear.

Ask them to identify the plate they intend to send before it leaves, and let your receiving and integration people know what must be checked on arrival. You have already lost enough time to two things being called the same.

Has collection been booked, or only offered?

Replacement received and checked against the agreed drawing. The designer confirmed the shoulder and seating face match. The original plate has been collected. Our integrator still has the installation work; the supply mismatch is finished.

And stores gets the right reference at last.