When producing a set of engineering drawings for products we tend to specify the materials used for the part in the notes. For example if it's a moulded part we'd specify PA6 GF20 and then the manufacturer and the manufacturer's code. We then store the TDS for this material in the technical file. We have a new QC guy who is now insisting that we put the polymer TDS on the engineering drawing now - literally paste it into the drawing. This seems wrong to me for several reasons but I'd like to know if anyone else considers this as correct or not.


2 Answers 2


Consider who needs to see the drawing outside your company (customers, for example) and whether you want to show them all the contents of the TDS. Are you giving away your "trade secrets", for example? Could your competitors use this information against you?

Also, if you have 10,000 parts all made from the same material, do you really want 10,000 copies of the TDS, one on each drawing? What happens if you update the material specification at some future date? Somebody is going to wonder why two specifications of "the same material" on two drawings are different - unless you re-issue all 10,000 drawings with the updated TDS, of course.

There might also be a legal question: if part of the TDS is actually produced by your material suppliers, not by yourselves, do you have their permission to copy and republish it?

  • $\begingroup$ I think this covers it, partly about "secrets" specifying a heat treatment process by code is standard and listing a material by code as well... $\endgroup$
    – Solar Mike
    Oct 22, 2018 at 9:21
  • $\begingroup$ Thank you both for your comments. The drawings are produced and stored by us on our SAP system but issued to our sub-contractor - they make the components and supply the complete assembled product. $\endgroup$
    – Judd
    Oct 22, 2018 at 10:14
  • $\begingroup$ So if you want to do this, you need to ask yourself if you trust your subcontractor not to let anyone else see the information. Note, "getting them to sign an NDS" is not the same as "trusting them never to breach the terms of the NDS, even if only by accident." Once the information has "escaped", winning a court case against the guy who leaked it and being paid damages doesn't make it secret again! $\endgroup$
    – alephzero
    Oct 22, 2018 at 14:38
  • $\begingroup$ I think it’s worth simply asking why the new QA guy is trying to change the way you have been operating and on what grounds. It sounds like he simply doesn’t want to review as many items. Engineering drawings are technical documents so unless there is a technical reason or overriding legal reason to make this change, you should have a discussion with stakeholders before making such a change. $\endgroup$
    – Secundus
    Oct 23, 2018 at 3:06

Is the drawing going to a customer, a vendor or in-house manufacturing?

a. If this is a customer be vague until you know for sure they are interested and actually need a more detailed specification. Then you can discuss who besides them will be viewing the drawings and you can make a decision on drawing content.

b. If this is a Vendor make sure your company has them sign a Non-Disclosure Agreement so they do not devulgue your company secrets without the possibility of a law suit. This is standard practice for most companies.

c. Also if this is a vendor, is this project for aerospace or government? If so then be vauge, the details can be determined after you get the PO through the procurement documentation. Don't try to tell the Vendor how to do his job. Specify the bare minimum for him referencing a standard whether it be a company standard or a published standard. Then you can make sure the key people get the info they need without giving away more information than is necessary.

d. If this is in-house, then write a company standard that can be referenced on all drawings it pertains to. Then if you need to change something you will only be changing the one document instead of 10 thousand drawings. I actually did this in our manufacturing department. It not only saves us 100's of man hours updating component and assembly drawings, it made a huge difference in errors due to outdated drawings. Mind you this only works well if you have a disciplined staff that tracks and controls its standard documentation properly.


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