1/2 BSPT thread in component

How do I get a 1/2 BSPT thread into my drawing 14 mm deep. BSPT is a tapered thread just to make it more difficult. if someone can draw it I will pay for it. Urgent! Or is there an extension.

Thanks all

How accurate do you need it, and for what purpose?

If only cosmetic, you could just use a suitable image.

If for 3D printing and to fit an existing thread, that would require more detail.

And do you need a female socket 14mm deep, or a male thread that long?

PS. Am I right in assuming that you want the thread to the 1/2" BSPT standard (max outer diam 0.825in) not 1/2" outside diam?

The standard seems to call for a 1 in 16 taper on the OD.

“The taper rate for all NPT threads is 1 inch of diameter in 16 inches of length (3⁄4 inch per foot or 62.5 millimeters per meter) measured by the change of diameter (of the pipe thread) over distance of thread. The angle between the taper and the center axis of the pipe is tan−1( 1⁄32) = 1.7899° = 1° 47′ 24″.”

You can use the “Draw Whorl” extension. I haven’t used it before, but it says it can draw tapered threads.

Hi John
Female thread. In mm the thread is Max just under 21 mm Dia or 0.825 as you suggest. It is for printing. I have noticed with threads that a complete thread if created normally does not create a perfect thread. It starts with a part thread. The actual thread needed is 12mm deep so I was going to cut 1mm off top and bottom of 14mm but looking at it the pitch may be more than 1 mm so may need 16mm of thread. Link to thread details http://1.bp.blogspot.com/--WY_a4hOEXM/VBeoBMx-UQI/AAAAAAAAA0o/LQah0D89iok/s1600/brass-reducing-bush-3-4-bspt-male-x-3-8-bsp-female-fitting-[2]-2032-p.jpg

I’ll Try that Thank you!

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For 3D printing I would recommend doing what foundry people have long done: plan on drilling and tapping the threads after the part is made. Surprisingly small flaws in a threaded hole can lead to leaks!


Never though of that. Maybe some old ways are still the best eh?

Best regards

Hi Forestr

Tried it, fascinating! have not found a way to integrate it yet. I can draw the thread but cannot loose the lead in or out. I will keep at it for a while.


Hi Forestr

I cannot get the female version of this thread. Where did you get it, or how

Best regards

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