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I found these "shopping" at the dumpster in the industrial park my shop is in.
At first glance they looked like acme threads, so I grabbed them, a quick check online
seemed at first to confirm that it's a 1" - 6 acme thread, so to double check I ordered an
inexpensive acme nut from McMaster, it was no go, even looking at the threads in
the nut I knew it wasn't going to fit, and it didn't.
Looks like is deeper than Acme and the crests rounded.
Measure the root diameter with a homemade sheet metal gauge if you can not get in with calipers.
Figure the ratio pitch to thread depth.
Since it appears not to be a buttress thread or a square thread, it is one of the Acme or Stub Acme threads as already mentioned. It may be a metric Acme or a home made screw.
The metric Acme is mentioned here: http://www.engineersedge.com/hardware/i ... reads1.htm
Your difficulty in finding a nut may be why it was in the dumpster.
--earlgo
Before you do anything, you must do something else first. - Washington's principle.
I have three or four old acme looking threads, just like yours. Same experience. 1" x6 thread. Nothing fits. Mine are old, old, old. Came out of an estate sale from a retired machinist, sitting in the corner of a garage covered in rust and cob webs. I thought they might be useful as sort of a giant machinist jack. But, no dice as I can't find a nut to fit the threads. So there they sit, making more rust.
Whatuse would a stub acme thread be on a 1" solid steel shaft??
Glenn
Moderator - Grand Scale Forum
Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge
Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
I found this - http://www.dependableacme.com/thread-gage-guide/
it seems to not be acme, at least according to the guide from the above link, it could be that this is a variation on an acme thread ?
Anyone remember the work stools and chairs that had to be spun to raise and lower ?
Were those acme or a wood thread like you would find in a push broom handle ?
The base of the screw tells me that it was used in adjustable office chairs. The older high chairs, stools had an actual acme thread but they found that the wear was more side to side. It had to be quick adjustable so had to be a coarse thread.
spro - That's what I was leaning towards, that it may be some odd acme-like for furniture use, there are quite a few furniture
manufacturing places in my industrial park.
Bill - definitely not metric, the OD measures 27mm and nothing in McMasters catalog matches, and at $40 + for a nut
I wasn't going to order one, not that curious.
I ordered a acme thread pitch gage ( always wanted one and it was on sale ) and it definitely is an odd thread none of the
pitches fit. They go in my scrap pile, maybe I'll turn them down and use them as rod blanks or see if I can thread a nut based on the odd pitch.
Thanks all for chiming in.
