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[flamingtail]

Hi All, I'm fairly new to this game and need a little help. I'm building a Moriya Fan, with a Stirling Engine. The plans show threads of 8-32, 1/4-28, 8-36 and 3-48. I'm at a loss as to what they mean...... Any help would be much appreciated. I've attached a small part of the drawings for reference. Many thanks for this opportunity.

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[stubee]

Hi and welcome ...

Thread sizes are read 'size/diameter' by 'teeth per inch or TPI for short)

So what you have are:

8 x 32tpi
1/4"x28tpi
8 x 36tpi
3 x 48tpi

All I think are UNF or UNC threads ... most engineers however use whatever 'they have in the box' for threads

The best visual weblink I could find is here that explains the basics www.wikihow.com/Read-a-Screw-Thread-Callout

Good luck with the build ;D

Stu

[alanstepney]

What you have there is an American drawing, and they use ASME threads, that are designated as you mention.

8-32 is 0.164" diam x 32 tpi
1/4" -28 is, of course, 1/4" diam x 28tpi (A UNF thread)
8-36 is again 0.164 diam but this time is 36tpi
3-48 is 0.099 diam by 48 tpi

The closest, or a close (British) thread for each is:

3BA
1/4" BSF (or 1/4" brass)
3BA again
and
7 BA

[jasonb]

You have a bit of a mixture there

8-32 and 3-48 are UNC
1/4-28 and 8-36 are UNF

Have a look at this table, it lists a vast number of threads, find the ones on the list and then look for the nearest equivalent in what you want to use such as Metric or BA.

For example 8-32 is very close to either M2.5 or 7BA.

pages.cs.wisc.edu/~bolo/workshop/thread.html

Jason

[isc]

I use UNF 10-32 (3/16"), 1/4, 5/16, 3/8,1/2 a lot because its a good fine thread, and I'v got the gear. small thread 1/8w. I also now mix in some metric.
Use what you have, and only buy what you need, and get good quality stuff.isc

[flamingtail]

Thanks folks, this has been a real help. I had no idea I would get such comprehensive answers and so quickly! Just goes to show how old and new tech can mesh perfectly together.......As a reward - a short joke.
A man and his friend are playing golf when a hearse drives past. The man, with his club at the ready to swing, stops and lowers his club and then takes off his cap and bows his head.
His friend, touched by the man's solemness says "That was very respectful of you"
To which his friend replies "Well she was a pretty good wife......."
Thanks again all.