How do I apply the threads and the h7/H7 tolerances to the draw? (CNC)

It is not necessary to draw the threads on your 3D file or provide a 2D table/pdf

How to design Threads for CNC:

Due to the absence of unified criteria for the definition of the threads between the various CAD packages, it is not necessary to draw the threads in your CAD program: you will only have to draw the holes with the correct ISO diameter (a simple cylindrical shape) of the desired thread, for example 4.2 mm for an M5.

Click here to download the Threads Table and H7/h7 Table with their tap-holes and shafts dimensions about all the offered standards: Metric, Metric Fine Pitch, Gas/BSW, UNC, UNF and PG

The blind hole threads are generally made up to a maximum of 3/4 of the hole and the maximum thread depth is usually 4-5 times the diameter.

In the case of too deep through threads, these will be made half by part, unless otherwise indicated in the notes form or agreements made with the staff.


Some advice for your design:

The threaded shafts (external threads) can be made up to 2 mm at the end of the cylinder, if closing is necessary you will have to draw a 2mm groove on the bottom at least as deep as the thread pitch.

Have a look at the example down here:

Threaded shafts


How to set threads on your uploaded file:

The internal or external threads that are FREE and the holes that can be threaded are automatically identified by the online Quotation Page following this legend:

Holes legend

Once uploaded a file, click on the "OPEN" button in point 2 of the Quotator:

Open button

You will be presented with the following screen, from here you can select the holes or shafts recognized on your part to assign the compatible features (orange squares), you can filter them and make a multiple selection through the various menus (green squares) to apply to the holes with the same specs the same features in a few moments.

Select holes or shafts

Furthermore, by selecting a single row in the table, the respective hole will be highlighted in the preview on the left:

highlighted hole