Tips and Tricks: Tapered Thread Milling

In PTC Creo NC, you have long been able to create milled threads. But with PTC Creo 3.0, you can now create tapered thread milling toolpaths.

Tapered threads are useful where you need a tighter seal than might be possible with a standard straight thread, for example, in plumbing applications where gases or liquids flow through a joint under pressure.

Tapered pipe and elbow. (image Wikipedia)

In this post, you’ll see how to create an internal tapered thread that follows the US NPT standard and one with user-defined dimensions. But before you start, create a thread milling NC sequence. If you’re not sure how to do that, visit the PTC Creo Help.

To create an NPT thread, follow these steps:

1. Click Mill > Milling > Thread Milling.
2. If you haven’t already, click the Dynamic Preview button to make sure you can see the tool path.

3. In the model tree, right click the previously created thread milling sequence, and then select Edit Definition.
4. In the Thread Milling tab, click the Standard Pipe Taper button from the list of thread types, to cut an NPT thread for a standard pipe taper. In this case no other parameter is needed because you are using 1.7899 degrees as the TAPER_ANGLE. In the Graphics window you can see the resulting toolpath.

To create a user-defined tapered thread, follow these steps:

1. Click Mill > Milling > Thread Milling.
2. In the model tree, right click the previously created thread milling sequence, and then select Edit Definition.
3. In the Thread Milling tab, select the User-defined Taper button.

4. Click the Parameters tab, and in the TAPER_ANGLE field, type a value.

If you’d like to see a demo, PTC University has an online tutorial available. Just click the video below to view the tutorial for free; no login needed.

If you’d like to see more, I’d recommend a visit to PTC University Learning Exchange. You’ll need to create an account—but it’s free and there are 700 more PTC tutorials just like this one waiting to show you how to use PTC Creo effectively.

Use the Learning Exchange to check out titles like Tool Axis Control for Cut Line Milling, Helical Three-Axis Trajectory, and Creating Drilling Sequences.

For additional background, explore multi-pass thread milling, made available in PTC Creo 2.0.