Any sources for coarse 1/4" thread other than 1/4-20?

1. Zip
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## Any sources for coarse 1/4" thread other than 1/4-20?

Considering a project that will require a stationary part to move left and right from center with less than one revolution of the screw head. Just tried 1/4-20 but it only travels about 80% of the travel needed, any ideas for a screw and tap source?

Thanks

2. Stainless
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Why not use a 3/8-16 screw?

Or, Roton has 1/4-16 Acme threads and nuts:

1/4 - 16 Right Hand Acme Lead Screws & Nuts for Power Transmission - Roton Products, Inc.

3. Diamond
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Originally Posted by Zip
Considering a project that will require a stationary part to move left and right from center with less than one revolution of the screw head. Just tried 1/4-20 but it only travels about 80% of the travel needed, any ideas for a screw and tap source?

Thanks
WoW.....let's put some real numbers here..."About 80%"...

What travel doo you want, for each revolution of the leadscrew ?

4. Or, have someone make a thread with whatever pitch you want, just be mindful of how weak it becomes when the minor diameter gets smaller and smaller.

Regards.

Mike

5. Aluminum
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A 1/4-20 thread travels .050” in a full revolution.
The OP needs to tell us the distance required then figure out the fraction from there.
20 TPI = 1/20 = .050”
If my math is right and 20 TPI is 80% of the travel then 16 TPI is 100% of the travel. Or very close at .0625”

Sent from my iPhone using Tapatalk

6. Originally Posted by Finegrain
Acme ...

McMaster-Carr

Or, have someone make a thread with whatever pitch you want, just be mindful of how weak it becomes when the minor diameter gets smaller and smaller.

Regards.

Mike
As DavidR8 points out if 20 TPI gives 80% then 16 TPI gives 100%. Anything courser than 16 TPI will give more than 100%.

Re "... whatever pitch you want, just be mindful of how weak it becomes when the minor diameter gets smaller and smaller." (unless I misunderstand you) a finer thread is not only stronger but is better at withstanding vibration.

1/4-20 is UNC. If you want less than 20 TPI (for example 16 TPI) you'll have to go up in diameter. Post #2 might be a solution.

7. Originally Posted by Gordon B. Clarke
Re "... whatever pitch you want, just be mindful of how weak it becomes when the minor diameter gets smaller and smaller." (unless I misunderstand you) a finer thread is not only stronger but is better at withstanding vibration.
I think you do . Larger pitch, e.g. 16 instead of 20 >> smaller minor >> weaker fastener.

Regards.

Mike

8. Diamond
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1/4 x 16 tap 1/4-16 Special Pitch Plug Tap, High Speed Steel all for \$8.90

'' die 1/4-16 Special Pitch Round Die, 1" Outside Diameter - High Speed Steel '' \$11.50

Home & dry for under 21 bucks HAS to be a deal

9. Zip
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Originally Posted by Limy Sami
1/4 x 16 tap 1/4-16 Special Pitch Plug Tap, High Speed Steel all for \$8.90

'' die 1/4-16 Special Pitch Round Die, 1" Outside Diameter - High Speed Steel '' \$11.50

Home & dry for under 21 bucks HAS to be a deal
Thanks all....this is what I was looking for!

10. Originally Posted by Limy Sami
1/4 x 16 tap 1/4-16 Special Pitch Plug Tap, High Speed Steel all for \$8.90

'' die 1/4-16 Special Pitch Round Die, 1" Outside Diameter - High Speed Steel '' \$11.50

Home & dry for under 21 bucks HAS to be a deal
When you're right, you're right. Must admit I was surprised that it existed.

11. Titanium
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Originally Posted by Gordon B. Clarke
When you're right, you're right. Must admit I was surprised that it existed.

C'mon, you can tell me.
If this was in the new format Metrology forum, you'd have deleted your own post because it was non metrology related.
So why do you feel it is right to post verbage here that adds no content?

12. Titanium
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Don't get me wrong, i have no problem with a comment like you have made, but you have already stated that it's unacceptable and will be deleted in *your* forum?

To me, comments (like you posted) are acceptable - a forum is "just like talking". Discussion if you will.

13. Diamond
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As others have said, 1/4-16 gives you exactly 100%, calculating from your 80% and 1/4-20 numbers. But that is an EXACT number, not an "about" number which may wind up being on the shy side of what you need.

If 1/4-16 is exactly what you want, then just search for that. Here's one:

https://www.mscdirect.com/product/details/01205749

14. I'm surprised no one has mentioned a two start 16 pitch, giving you 16 pitch but the strength of 32 pitch. Play with whatever numbers you want. Make you own tap or have one made, screw is pretty easy to cut on a lathe.

15. Diamond
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Originally Posted by Hardplates
I'm surprised no one has mentioned a two start 16 pitch, giving you 16 pitch but the strength of 32 pitch. Play with whatever numbers you want. Make you own tap or have one made, screw is pretty easy to cut on a lathe.
Some double lead taps off the shelf here Regal Cutting Tools

Tom

17. Originally Posted by TDegenhart

Tom
This is a manufacturing and machining forum....no? Even a milk jug has multi start threads

18. Originally Posted by TDegenhart

Tom
I e never seen one in person, I'd love to get my hands on one just to check it out.

19. Titanium
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Originally Posted by plastikdreams
I e never seen one in person, I'd love to get my hands on one just to check it out.

make one,,good exercise on lathe use

20. Originally Posted by jrmach
make one,,good exercise on lathe use
It's a good idea...maybe some day