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Using a screen recorder. Thank you for the comment!

​@@encole7224Thank you for your answer but I think I did not express my question perfectly. I meant I watched your previous videos about how to create male and female NPT threads in SOLIDWORKS. I applied those contents for creating my male and female NPT threads. But when I want to mate the two parts I can't mate them properly using screw mate in SOLIDWORKS and the threads of female and male counteracts with each other. In your video the Male part rotates in the female part without any interactions between threads. I want to know how you did that?

You are right on both points: it should be atn (1/16, which is the combined angle / divided by 2), for the half of the revolve feature. So, atn(1/16/2); or atn(1/32). For the second point, you are correct about practical manufacturing to the model. Tolerance is very small for the actual angle derived as atn(1/32), or angle measured as atn(1/16) divided by 2 after. Thanks for the comment!

There is a separate video for external thread. Same size, NPT 2". Dimensions are the same, except the internal thread has a starting bore diameter which is different from the external threads nominal dia. 2.375. The rest of the dimensions: tooth height, pitch, angles, are the same. Thank you for the question!

@@encole7224 Thanks for your reply. Where can I find the two charts? And are these the same threads used on electrical conduits?

@@Technoboy928 Take a look at Machinery's Handbook. Available on Amazon, many other places. For electrical conduits, yes, NPT pipe joining is common. Vibration resistant, thermal expansion proof, leak-tight, long lasting pipelines. Typical in plumbing lines for fluids, air. Wiring cables can also be run through such pipelines.

@@encole7224 Thanks a lot.

Camera is on a long stick. Cameraman is away from the action.

Cameraman always survives! Camera was on a long stick.

Cameraman always survives. ) Besides, the camera was on a long pole. The operator was away from the action line of sight.

Camera is on a long stick. Thank you for the comment!

The camera is.

Test was stopped to tighten everything. I know )

For external threads, take a look at this tutorial: th-cam.com/video/PRIaboUs_F8/w-d-xo.html Use table values for 4-inch threads. O.D. of pipe 4.500. Height of thread: 0.100. All moves are the same for this size as for NPT 2" in the tutorial. Thank you for the comment!

@@encole7224 Except for the thread cut, which must have a center separation of 4.33438, which it says in the table, right?

@@Dj_CerrilloYes, that's the pitch dia. at the beginning of external thread. This is another way making the thread, starting with this diameter and work from there with the angle and tooth height. I think the way I made it in this video was starting from the Nominal Dia. and working from there. Either way will work. The important point is to make the actual thread to meet the gauge inspection within tolerance. CAD model is just a reference for the shop making it.

@@encole7224 I thank you infinitely for answering me, it was very helpful to me, since I am making a design to adapt an ultrasonic sensor to a 4-inch coupling and I am going to print the thread along with my design on a 3D printer to see how it goes. Beforehand thank you very much.

@@Dj_CerrilloLooking forward to your progress!

Thank you for the comment, good point. The video is to demonstrate the process of making the thread. In practice, thread lengths are made to a specific application, matching the length of the mating part. As long as the taper, the pitch and the root diameter are within the spec the parts will engage. For example, take a look at NPT taps, they have 16-17 full threads in case the internal bore needs to be longer for some reason. Technically, you have a good point about adhering to the standard.

Thanks Charlie for the comment. You are correct about the model, where the root of the teeth is not parallel to the taper, it's an oversimplification in the model. The tooth root line should be aligned with the taper. However, in the real world when the threads are made, the cutter point moves along the spiral at the taper angle. This makes the root parallel in the actual threads. So, if the model is used to program the CNC, then it will work out.

@@encole7224 This seems like an odd oversimplification to make when it is really no harder to model it the way that it actually is. Essentially this tutorial would not be correct for someone trying to 3D print NPT threads from model for instance.

Thanks robertjustice! Your model may work out differently based on minor dimensional values you assign to features. This is really a design for manufacturing process where the final product needs several model iterations to be fully optimized.

Gauge needs to be flush with the front of threads. This is 5.01 thread engagement, a must for any NPT thread. Maximum thread engagement is 8 threads (dimension L2 in NPT charts). More than that is a discretion depending on the use case, and thread release. Helps?

Thanks Lucas, You are correct.

You are correct. In practice, although, the difference between arctan(1/32) and arctan(1/16)/2 is 0.0017 degrees. It is well below the manufacturing tolerance, so the angle will work out in the real world. The math was an oversight in the video, thank you for pointing it out.

Hi Pratik, this is a tolerancing issue. It's a good practice to make a trail part. You are doing it right. Adjust the dimensions (on your mill, lathe) within the tolerances. This is a try-and-adjust process, we always make NPT threads like that. Sometimes the customer has a part that is on the other side of tolerances, this needs to be accommodated. I think gauges are made to so many minimum thread engagements. In the video it's likely not the same, thus you are having the issues.

There are two pictures in the Instagram post: instagram.com/p/CdSANl_L8tX/?igshid=MDJmNzVkMjY=

This is to make sure the clean cut. Sometimes Solidworks has a problem with line to line cuts, where the sketch borders another feature. This .001 offset makes sure the sketch overlaps the adjacent edge of the part, guaranteeing a clean cut.

@@encole7224 thank you so much. This is very helpful.