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deltaenterprizes
08-25-2009, 10:07 PM
I don't know how to post pics here so I will try to describe it. It is a fairly common thread the end of mop handles, paint roller extension handles,push brooms, etc.
It is about .700''' major dia,.614'' minor dia, the raised part of the thread is about .100''wide, the grooves are aprox .100'' wide, thread depth is about .044''.
It almost looks like a square thread but not deep enough, maybe a 5 TPI acme.
This is a free fer job so I am not loking to spend a lot of time grinding a tool only to find out it is metric.
Any ideas?

Fasttrack
08-25-2009, 10:11 PM
Personally, I would free hand grind the tool using an existing thread as a gauge. Those things fit so sloppy-like that your thread probably won't have to be perfect anyway. Shouldn't take more than 15 minutes at a grinder.

mechanicalmagic
08-25-2009, 10:28 PM
I just measured the one on my broom.
OD .73"
Minor .60
5 TPI
60 degree included angle.
Looked to be a standard type thread, not rounded over, but with the crests too large, and the root too wide.

Sorry, I don't have thread wires for 5 TPI.

DJ

doctor demo
08-25-2009, 10:31 PM
I did 4 of those a couple of months ago for a guy that had some realy nice telescopic alominum handles with cast junk end riveted in.
I made the new ones out of alum, bar mystery aloy, and thru bolted them in.

I just grabbed a hss tool that was previously ground for a o ring groove and put some more side clearence on it. After getting the thread root dia, close I used a file to finish off the o.d.

Drilling out the rivits , grinding the tool , making the parts and re assy. with thuu bolts took about an hour and three quarter for the lot of them.

Like Fasttrack said, the threads are not NASA specs,

Steve

Lew Hartswick
08-25-2009, 11:04 PM
I made a bunch of new ends for the push brooms at school (for
the metal shop) and I just turned an Acme thread 5 tpi and made it fit for
diameter. Some of them have been in use for several years now. Of course
the broom head is wood so it may "conform" a bit better than plastic of a
paint roller.
...lew...

wierdscience
08-26-2009, 11:15 PM
Did you ever think there were so many?:)

http://www.spinelli-group.com/thread.htm

gwilson
08-27-2009, 09:45 AM
I make wood threads by using a router held on the toolpost of the lathe. Of course,CORRECT wood threads are V threads with 90 degree angles,rather than 60 degree.Thus,feeding a bit in at 45 degrees makes a perfect old type wood thread with no chipping.

oil mac
08-27-2009, 12:07 PM
I once on a couple of occasions, Made a two or three of these threads, , for a couple of our painters, to make a special tool when i worked for the local authority, This type of thread is called a stub acme, and is only half the depth of the conventional acme, (i believe you may get the correct specification in Machinery Handbook, I think in the past that is where i saw it)
As regards making it, it was easy,as it was machined in dural, and i used the tool i have made for acme threads.

deltaenterprizes
08-27-2009, 03:18 PM
Thanks for all the answers, I will try the 3/4-5 stub acme.
I used a tool ground for 5 tpi Acme , threaded to the minor diameter and it works great.