Threaded rod that is not threaded

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airscapes
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Joined: Wed Jan 31, 2018 11:36 pm

Threaded rod that is not threaded

Post by airscapes » Mon Mar 09, 2020 4:00 am

Anyone ever run into threaded rod that is not really threaded? Home Depot sold this.. really put the FIRST robotics team I mentor with up against the wall. Could not figure out why the nut would not go on until I got it home and looked at it under magnification...
Top pic good 1/4 20 threaded rod bottom is what we were fighting with...
Anyone ever see anything like this?? How could this have been made accidentally??
no threads.jpg

jferguson
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Location: St Petersburg, FL

Re: Threaded rod that is not threaded

Post by jferguson » Mon Mar 09, 2020 1:23 pm

Amazing. It would be really wonderful to learn how this happened.

"Here George, make them like this" George having forgotten to wear his eyeglasses that day.

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rpollack
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Re: Threaded rod that is not threaded

Post by rpollack » Mon Mar 09, 2020 2:08 pm

We've used a lot of threaded rod over the years and i've never seen that...

Gwhite
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Re: Threaded rod that is not threaded

Post by Gwhite » Mon Mar 09, 2020 2:11 pm

Worn out die or cutting tool, combined with poor quality control to let it out in the world.

I once bought a medium price drill bit set. Most of the bits were fine, but one wouldn't cut at all. The spiral was right hand, but the tip had been ground as if it was a left hand bit.

Here's a picture of a really cheap drill bit compared to a normal one. A friend referred to it as being made from the finest "Chinesium". I was drilling 1/4" thick mild steel with an electric hand drill. It caught, and wound itself up into the more compact form show...
Chinesium Drill Bit.jpg

jferguson
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Re: Threaded rod that is not threaded

Post by jferguson » Mon Mar 09, 2020 5:06 pm

Well GWhite, that was one way to get a threaded rod.

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ednisley
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Re: Threaded rod that is not threaded

Post by ednisley » Mon Mar 09, 2020 9:28 pm

airscapes wrote:
Mon Mar 09, 2020 4:00 am
How could this have been made accidentally??
Those threaded rods are rolled, not cut: if the operator misaligns / swaps the rollers, the rod won't feed and you get those pretty rings.

A promo video gives the general idea:

https://www.youtube.com/watch?v=rwArBBcUNr4

A few minutes on Youtube after searching for "thread rolling" will have you wondering why any machine operators have any fingers …

airscapes
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Re: Threaded rod that is not threaded

Post by airscapes » Mon Mar 09, 2020 10:34 pm

Thanks Ed! I knew someone here would be able to shed some light on this!

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