How to use threaded inserts ? [MAKE wiki]

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====== How to use threaded inserts ? ======

**Overview**

Threaded inserts allow you to add durable, reusable metal threads to your 3D printed parts. This is essential for parts that need to be assembled/disassembled multiple times, or where strong screw connections are needed. 

Note that threaded insert is a good solution but not the only one. **A good practice is also to have a pocket in your design where you can simply put a nut inside.**

This tutorial covers the process for heat-set threaded inserts and includes both design and installation instructions.


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**Step 1: Design the Hole in your CAD model**
  * While modeling your part, design a hole at the insert location.
  * Use the exact hole dimensions provided by the insert manufacturer, like hole diameter (D3), depth (L) and minimal wall thickness (W) around the hole.

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Tips:

  * Take some margin with the depth (at least 1mm more than the value)

  * Add a chamfer to help guide the insert in smoothly (0.3~0.5 mm)

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**Step 2: Print your part and check the hole fit**
  * Once printed, try placing the smooth end of the insert (D2) into the hole by hand.
  * If it doesn't fit: Don’t force it! Ask your mechanical workshop coach for help using a precision drill bit to correct the hole diameter.
PET-G can shrink slightly after printing, so minor post-processing is normal.

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**Step 3: Place the insert by hand**
  * Place the insert manually into the hole, starting with the smaller and smooth diameter end (D2).
  * It should sit snugly but not be forced in.
  * It only needs to start in the hole, not go all the way in — the heat will do the rest.

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**Step 4: Prepare the insert tool**
  * Choose the correct tip size for your insert.
  * Mount the tip on your insert placement tool (**while cold!**).
  * Set the temperature to the printing temp of your filament: 230 °C for PET-G

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**Warning: This tool gets very hot. Always place it back on its stand when not in use.**

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**Step 5: Heat-set the insert**
  * Hold the heated tool vertically and gently press the insert.
  * Apply light, even pressure.
  * As the plastic heats up, the insert will begin to sink into the part. 

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**Tips:**
Don’t force it — let heat do the work.

Keep the axis straight to avoid misalignment. 

Watch the sides of the part — if it starts to bulge, stop. You may be overheating or pressing too hard.

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**Step 6: Make it flush**
  * Once the insert is fully seated, you can use a flat metal tool to gently press it down, ensuring it's flush with the surface of the part.
  * This step helps with cosmetic finish and mechanical alignment.

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**You're Done!**
  * **Turn off your tool and let it cool down safely.**
  * **Don’t touch the metal tip — it remains hot for several minutes.**

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👏 Your insert is now permanently embedded and ready for screws!
Don’t overtighten screws — inserts are strong, but the surrounding plastic can still deform.

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