Supplier wants manufacturing process notes on drawing 2

[LKENNEDY]

We have a supplier who regularly comes back with feedback of specific process notes that he thinks should be included in the product drawing.
E.g. there is a recess on one of our parts, and he asked for a note that says "18 x 5 x 5 recess machined post fabrication" as the part was going to be oxy cut first.

I am very new in my role here so am unsure if what he is asking for is reasonable but have always under the impression that the part/product drawing should contain info critical to form and function -Whichever way the manufacturer decides to make it is not really my concern as long as the parts are coming back within tolerance and passing FAI.
Simply, I don't want to include these type of notes - particularly in case we changed supplier and now the drawing is holding them to someone else's process.

With the same supplier we're having an issue where on one part, they drilled holes to 24mm instead of pre drilling and tapping them to M24. The hole callout was very clear that it is a tapped part and now they are asking for notes on the DXF too so this doesn't happen again.

Again, don't want to include this information, as I see it as completely their fault for relying solely on a DXF and not consulting the drawing we also sent. This has put a lot of pressure on the timeline to get the parts re-done. The rest of the assembly is sitting in the workshop waiting to be finished.
Do I just suck it up and put notes on a DXF for them to try and prevent this happening in the future? Or just insist that they have to read the drawing too. Seems insane to me that they wouldn't look at both. Why am I even sending a drawing if it's not being utilised?

Any help is sincerely appreciated.

 

[3DDave]

Those are methods required to produce a particular result.

 

[Burunduk]

Those are specifically methods that produce outcomes that meet engineering requirements. If they only said "particular results" then without context, "particular" could mean just anything. If you specify on the print that a feature has to be surface ground while the given tolerances can be held and the same functionality achieved by face milling, there are also "particular results" - one of which is costs increased unnecesarily.

 

[3DDave]

Aesthetic finish is not an engineering requirement, but one driven by marketing. It may be achievable only by a particular method that is known not to have unwanted side effects.

For some reason you again misquote to support your argument. Why do you do that?

 

[3DDave]

"unless the method is required to produce a particular result"

In case "required" was simply forgotten. But you memorize everything and repeat verbatim, so not likely forgotten.

 

[LKENNEDY]

Thank you to everyone for your contributions. You've given me a lot to think about.

 

[Burunduk]

"Aesthetic finish is not an engineering requirement, but one driven by marketing."

It is a requirement documented by engineering and characterizing the finished part. You cannot deliver a finished part that didn't go through the specified manufacturing process and has the same characteristics. That clearly differs from what is discouraged - for which the standard brings an example within the fundamental rule, because it is not as laconic and vague as you would like it to be.