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View Full Version : Hmmm...something is a bit off with that All-thread rod



wierdscience
12-20-2016, 08:22 PM
We sell bulk all-thread rod at work,fair amount of it every year.Sold some 12' foot lengths of 1/2-13 this morning.Customer calls up an hour later and says one piece is defective and no matter what a nut won't start on it.So I told him to bring it back and we would gladly swap it for another piece.

He came in and this is what we have-
http://img.photobucket.com/albums/0903/wierdscience/019_zpsdtwtzxtt.jpg (http://smg.photobucket.com/user/wierdscience/media/019_zpsdtwtzxtt.jpg.html)

Let's call it 1/2-13 pitch grooved rod,since they forgot to include the helix :D

Selling bulk fastners,one does see all manner of the odd defect slip through.I've seen bolts with no threads,bolts in the same condition as the all thread and nuts with no thread.This is the first time I have seen all thread with this defect.

What I am wondering about is just how this happened,since IIRC the thread rolls also feed the rod through the machine?Seems it wouldn't advance without a helix being generated?

Spin Doctor
12-20-2016, 08:27 PM
1/2-13 TPI -NH for NO HAND :confused:

paul463
12-20-2016, 08:27 PM
Many years ago I got a new 5/15" bolt from the bin like that.

I tried and tried to get a nut started before I realized what was going on.

Hasn't happened since.

JCHannum
12-20-2016, 08:32 PM
That all thread is kind of like the guy who says he is ambidextrous because he can't write with either hand.

Doc Nickel
12-20-2016, 08:35 PM
What I am wondering about is just how this happened,since IIRC the thread rolls also feed the rod through the machine? Seems it wouldn't advance without a helix being generated?

-It's an adjustment issue. Since the rolls still have a helix, the rod still progresses through. They're just spaced wrong- and it doesn't take much.

My local college machine shop teacher collected curios like that, and had a chunk of 5/8" allthread identical to it, as well as the usual Allen head bolts with no hex, bolt shanks with no thread, deck screws with no Phillips recess, nuts with no thread- or nuts with badly crooked threads, etc.

Doc.

KiddZimaHater
12-20-2016, 08:40 PM
Spun in the roll-form tool without advancing? But that wouldn't explain 12 feet of it.
???????????????

CalM
12-20-2016, 08:59 PM
Some years ago, I entertained myself by crawling all around large aircraft while they were not flying. (A&P)
A some point, I requested a bag of AN flat head screws to replace the damaged heads on the fasteners of an access plate.

Not one of the darn things would run into the captive nuts riveted inside the structure.
Close examination of entire content of the bag revealed the exact same defect as observed by the OP.

Crap happens, at all levels.

wierdscience
12-20-2016, 09:02 PM
Video shows a possible explanation,I always thought thru feed thread rolling used three rolls like the thread rolling heads used in turret lathes,but looks like it's just two rolls with a support rest.

https://www.youtube.com/watch?v=gkT3vSUtHFI

Mike Nash
12-20-2016, 09:56 PM
I have a die in a Western Auto tap and die set that could make threads just like that, though smaller, if I could just get it to start.

Paul Alciatore
12-21-2016, 01:23 AM
Seems like if the rod was not fed past the rollers at the correct speed then the helix could disappear.

I think that piece of grooved rod is a sales opportunity. "Unique item! Grooved rod! This can be yours for just $10,000 plus shipping and handling."




Video shows a possible explanation,I always thought thru feed thread rolling used three rolls like the thread rolling heads used in turret lathes,but looks like it's just two rolls with a support rest.

https://www.youtube.com/watch?v=gkT3vSUtHFI

George Seal
12-21-2016, 01:39 AM
But Wait

where you gona get another one
to go with Just Pay Extra Shipping & Handling

achtanelion
12-21-2016, 10:32 AM
Looks like ordinary radially splined rod to me. :-)

boslab
12-21-2016, 12:11 PM
Perhaps it could be used as a round rack gear for somthing?
Perhaps a depth stop or cnc machine
Mark

plunger
12-21-2016, 01:15 PM
I was at Industrial scrap (a large scrap yard ) .I often buy offcuts of metal for projects. They had bundles of 8mm threaded bar in three meter lengths.I asked if I could buy some and it comes out that the guy bought a container load from China but the nuts didnt fit. It must be the same problem. It turns out the China dealer refused to pay for the shipping of it and the guy landed up selling it as scrap. A hard lesson.

reggie_obe
12-21-2016, 01:22 PM
Perhaps it could be used as a round rack gear for somthing?
Perhaps a depth stop or cnc machine
Mark

Maybe it's truly scrap. Use it like rebar.

Peter.
12-21-2016, 02:28 PM
Many years ago I got a new 5/15" bolt from the bin like that.

I tried and tried to get a nut started before I realized what was going on.

Hasn't happened since.

Yeah damn those 1/3" bolts they always catch you out :D

Andre3127
12-21-2016, 03:25 PM
I remember hearing a story I'd read either on Practical Machinist about a defect twist drill. The helix started out RH, went neutral, then LH towards the shank.

macona
12-21-2016, 04:44 PM
I remember hearing a story I'd read either on Practical Machinist about a defect twist drill. The helix started out RH, went neutral, then LH towards the shank.

That was me. I posted the pic. I think the drill was so soft that the bit twisted instead of snapping.

winchman
12-21-2016, 06:17 PM
I've seen all thread like that (no helix) in a 3/4-10 size. There was also a section on the piece that was threaded but seriously undersized just before the helix disappeared. I guess some adjustment slipped during processing.

Paul Alciatore
12-21-2016, 11:49 PM
The standard charge for Extra Shipping & Handling is $974.52. No problem! What color do you want?




But Wait

where you gona get another one
to go with Just Pay Extra Shipping & Handling

wierdscience
12-22-2016, 12:12 AM
Wait! You forgot the MSDS compliance and Environmental charge of $269.95!

Lew Hartswick
12-22-2016, 02:04 PM
The "round rack gear" would be great (I could actually use it) IF it were 10 or 20 pitch but 13 Phew. :-(
...lew...

Glug
12-22-2016, 02:29 PM
Are you sure the invoice didn't say N'all thread-rod?

Jaakko Fagerlund
12-22-2016, 02:36 PM
Seems like if the rod was not fed past the rollers at the correct speed then the helix could disappear.
It is a self-feeding machine, the only way to get it do that not-at-allthread is by misadjusting the sync or phase between those rolls.