Sort of been there…it’s one of those “let’s cover our back” cases where they state more conservative tolerances just in case

We get several sheet metal parts with PEM inserts. Just state the tolerance clearly in you’re drawings. Had some other types of issues during prototyping (wrong inserts or bent) but none for being loose or fallen

Technically these parts are assemblies, not just a “part”. I usually add a note next to the holes table like “All X holes have a Tolerance of +/-Y”. Unless there aren’t that may holes/inserts, then it’s just a Tol call out on the dimension itself

We’ve even had cases of repeating orders where they come back saying “this tolerance is too tight for the process”, and I’m like “Brother, you’ve done it before. Why is it an issue now?”. No answer back and part arrives just fine 🙂

Hello,

Great question, and you are absolutely right in your analysis. The +0.08 mm tolerance is indeed too tight to guarantee consistently with standard laser cutting alone due to the natural variation in the kerf width.

To ensure your parts come out perfectly, we handle this in one of two ways, depending on how you prefer to receive your order:

Option 1: Xometry installs the inserts for you:

If you request us to supply and press the PEM inserts into the sheet metal, you don’t need to worry about calculating the exact hole sizes or tolerances.

What you need to do: Just provide a 2D technical drawing showing the sheet metal, the exact locations of the inserts, and the specific PEM part numbers/codes you require. Our manufacturing partners will take full responsibility for sizing the holes correctly and installing the inserts.
Option 2: We supply the sheet metal, and you install the inserts yourself:

If you prefer to order just the bare sheet metal and install the hardware on your end, we can still achieve that tight tolerance. To do this, our partners typically use secondary operations (like precision drilling or reaming after an undersized laser cut).

What you need to do: You must attach a 2D technical drawing (PDF) alongside your 3D model. Call out the specific holes and explicitly indicate the required size and the +0.08 / -0.00 tolerance. The 2D drawing ensures our quality control team and manufacturing partners know exactly what strict tolerances must be met during fabrication.
Both options are available through our platform. Let us know if you need any help setting up your quote!