Custom Thread Fields and Tags

[neinspam2XVWZ]

I'm experimenting with some custom threads creating my own Xml file in the Thread folder. I haven't found any post that explain in detail what each tag in the file does.  Some are obvious others not so.  For example;

 <Angle>55</Angle>

I assume the thread angle??

<ThreadDesignation>G 1/16-28</ThreadDesignation>

<CTD>G 1/16-28</CTD>

<TPI>28.0</TPI>

If the units are mm is this still threads per inch then converted to threads per mm??

<ThreadForm>8</ThreadForm>

Trial and error I figured out this is the designation for pipe thread.  What are all the valid thread forms ??

[MRWakefield · Accepted solution]

I've not managed to find any documentation on the structure of the XML or what certain tags are used for. Here's what I do know:

You're correct, <Angle>55</Angle> is the flank angle. 55° for Whitworth form, 60° for metric and UN etc., 47.5° for BA etc.

In my experience the <CTD> tag is always the same as the <ThreadDesignation> tag value. I don't know why this is duplicated.

<TPI> is usually used for Inch threads and <Pitch> for Metric. I'm not sure what result you'd get if you used <TPI> with Metric units or <Pitch> with Inches, I've not experimented to find out.

<ThreadForm> can be any of these values:

0: Trapezoidal

1: Sharp

5: Square

7: Whitworth (should add a radius to crest and root but there's currently a bug with this).

Hope this helps.

EDIT:

If it's of any use/interest I recently developed a Windows application for working with F360 custom thread files. You'll find a quick intro and link to it here. It's changed slightly since I posted the screenshots but it's not too different.

Oh, and I thought I'd see what happened if you used 'TPI' instead of 'Pitch', so I made a small test file using M6x1 as an example. I left everything the same but changed the tag to <TPI> and entered 25.4 (equivalent to 1mm pitch). When I tested this in Fusion it resulted in a thread with a pitch of 1.016mm! So, my conclusion is that Fusion takes the integer part of the <TPI> tag value and ignores anything after the decimal point. However, in some cases it must use the entire decimal value as there are some threads (UNC for example) that have TPI values of 4.5. Probably not important but it might be useful to someone.