# Source For Jam Nuts



## Azbrewer (Nov 24, 2015)

I am slowly getting my little Atlas Mk2 cleaned up. I have the treadmill motor going and my son turned the original wide pulley down to a useful 2L size pulley, I can run from about 200 RPM up to 3000. I have run into a minor roadblock though, I don't have the jam nuts for the compound slide gibb screws. I searched for but did not find any supplier for them. Normal 6-32 nuts interfere with the swivel. Any ideas?


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## Ulma Doctor (Nov 24, 2015)

mcmaster-carr

or you could re-thread a smaller nut to 6-32 since it's not a high stress area.
a brass nut would drill easy.
i hope the info helps out


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## Rob (Nov 24, 2015)

Did you try Clausing.  I think that the part # is M6-223.


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## Azbrewer (Nov 24, 2015)

After more searching I found them at McMasterCarr, shipping is more than triple the parts. I can't seem to find the Mk2 on Clausings website, but with a new part name I have found them at Amazon with free shipping. They are steel but will work.


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## RJSakowski (Nov 24, 2015)

DigiKey sells steel 6-32 nuts, 1/4" across the flats and .090" thick.  Their shipping costs arwe not as onerous as McMaster.

Bob
http://www.digikey.com/product-detail/en/4701/36-4701-ND/316272


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## Azbrewer (Nov 24, 2015)

Thanks, I would never thought to look at DigiKey.


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## RJSakowski (Nov 24, 2015)

When I had an electronic manufacturing business, I bought all my small fasteners from DigiKey.

Or try Mouser. 
http://www.mouser.com/catalog/catalogusd/648/2818.pdf

Bob


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## coolidge (Nov 24, 2015)

Both my local hardware stores carry jam nuts, I just purchased some last weekend. I gave up on the Lowes/Home Depot and shop at real hardware stores anymore.


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## chips&more (Nov 24, 2015)

You have the lathe, why not make them? It’s a simple enough project. And fun to share the end result on the HM. And I suspect you will not find the exact jam nut made to order in a store. You can make it faster and just like the original…Have Fun, Dave.


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## Round in circles (Nov 24, 2015)

Get a dozen or so standard nuts put them on a threaded bar or bolt , put it in the chuck & turn the first nut down to just over half thickness , don't put too much of  a chamfer on the face  edges/ flats as too much will see the nut slip inside the spanner . You only need to tale the f a smidgeon off the sharp cut edge not a full nut sized chamfer . I used a swiss needle file to kiss each flat on the nut before I used a spanner to take the nut off the rod whilst it was still in the chuck .
I only gave mine a kiss of chamfer and also ground the back of a ring spanner to remove the counter sink effect so there was as much metal to metal contact between nuts & spanner as possible . .

 When you put the newly made half nuts on the slide put them with the uncut face towards the slide as there will still be a slight lead in on that face & the biggest chamfered edge . The lead in recess helps take/ keep any tiny bits of crud on the threads or face of the slide out the way , instead of it sitting under the nut face as it would if you put the new cut face there instead . 

Using extra long 1 & 3/4  " Allen cap machine screws 
I ground down a set of high tensile steel Allen capped screws to make the gib adjusting easy with a " T " Key/Allen wrench . By calculating how long they should be and putting one of the screws thread portion first in a collet set a, then ground the spigot/tit end as well as cutting it off .


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## RJSakowski (Nov 24, 2015)

As I understand it, although the OP refers to the nuts as jam nuts, and indeed they are being use as such, the height of the nut is not an issue.  

His problem is that the standard nut has a 5/16" distance across the flats.  The OEM nut is 1/4" across the flats and a 5/16" nut interferes with the rotation of the the compound feed. The smaller nuts are commonly used in electronics equipment and suppliers like DigiKey and Mouser carry them.


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## Round in circles (Nov 24, 2015)

If you use full size nuts the thickness of them will frequently interfere with the side of the tailstock body the half nut  will sit in a slight milled out depression and miss the tailstock allowing you to get the cross slide close in for fine work and for getting  the maximum saddle travel

I had the same problem as the O/P

Let me find the thread and also see if I have details of  what nuts I purchased .
I get teh feeling that The description of the nuts you mention are not the size of the ones I got .


Back in a few....
BACK .

These are the nuts I purchased for my Sphere cum Atlas
10-32 (3/16") UNF Full Nuts Stainless Steel (Qty 10)

Now to find the thread,  you have triggered something in the old grey matter .... that may mean I had to reuse the old nuts after cleaning off the burrs for the very same reason of the AF sizes being awkward .& fouling the compounds rotation . ..


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## Azbrewer (Nov 24, 2015)

RJSakowski is correct in that my problem is with standard 6-32 nuts are 5/16" across the flats. My original search was for "Jam Nuts" which are 5/16" across flats but only 3/32" thick. I finally found I should be looking for "Small Pattern Machine Nuts" which are 1/4" across the flats. I have found them in multiple vendors and they will be on order when she says OK.


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## Round in circles (Nov 24, 2015)

Yes .. You are correct .... as I was searching for the post of what I did   it all came flooding back ..... I had to clean up the original nuts . 
That's one of the downsides of suffering a stroke ..some days the neck top computer crashes on the hard drive  .

Glad to hear you've got a handle on it .


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## Rob (Nov 25, 2015)

Coupling nuts are also usually the smaller size across the flats. You would have to part them off but they are easier to hold to turn the part round that is next to the machine. 

Also when looking for Atlas parts with clausing you have to call. They do not list them on there web site. A lot of the time parts are cheaper than you can get used from other sources.  It is suprising how well they still support the lathes.


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## my machine shop (Nov 25, 2015)

Clausing Service Center 1-800-323-0972


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## Azbrewer (Dec 2, 2015)

note, the gibb screws are 8-32 not 6-32.


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## Bill C. (Dec 3, 2015)

coolidge said:


> Both my local hardware stores carry jam nuts, I just purchased some last weekend. I gave up on the Lowes/Home Depot and shop at real hardware stores anymore.



I found if you need just a few common and sometimes odd bolts and nuts the local Ace Hardware and small stores carry a lot in those little storage boxes.


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## coolidge (Dec 3, 2015)

Bill C. said:


> I found if you need just a few common and sometimes odd bolts and nuts the local Ace Hardware and small stores carry a lot in those little storage boxes.



And for the really odd stuff nobody carries McMastercarr. This week I needed some 2 1/4 inch long 5/16-18 stainless button head screws, it had to be this exact length and nobody local carries that odd size, McMaster to the rescue, $8 for a package of 10.


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## RJSakowski (Dec 3, 2015)

Azbrewer said:


> note, the gibb screws are 8-32 not 6-32.


I checked my Atlas 6" and they are 8-32 x 1/4 nuts.  DigiKey has them.  If that is too much bother, take a 4-40 nut and drill and tap for 8-32.

Bob


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## RJSakowski (Dec 3, 2015)

Azbrewer said:


> note, the gibb screws are 8-32 not 6-32.


I am actually missing one myself so I'll make one this morning.  Here's what I would do.  

Find a 4-40 nut and a 4-40 screw x 1/2 or longer.  Cut the head off, thread the nut on, and mount the screw in the tailstock chuck .  Use the chuck to hold the nut while you mount it in the headstock chuck. This ensures that the screw threads are aligned with the spindle.   Loosen the tailstock chuck and remove the 4-40 stud.  Drill .136" and tap 8-32.  The whole operation will only take a few minutes.

Bob


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## Azbrewer (Dec 3, 2015)

I had ordered 6-32 and now await the 8-32 I ordered yesterday. For 5 bucks total, I will have 96 spare #6's and 100 #8's.


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## RJSakowski (Dec 3, 2015)

Azbrewer said:


> I had ordered 6-32 and now await the 8-32 I ordered yesterday. For 5 bucks total, I will have 96 spare #6's and 100 #8's.


OK.   I finished mine and made three extras to send to you  

It took less than a minute each.  I change the procedure slightly and just used a 4-40 tap to position the nut.  Saved one step that way.

Bob


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## Azbrewer (Dec 3, 2015)

While waiting for the nuts, got the Start/Stop control done. Using a Attiny85 to output PMW to treadmill controller for variable speed, another Attiny85 for Start/Stop, still designing how/where I can get a tach signal for RPM display which will be in between switches and rheostat. Want to read spindle speed directly so no need to convert back gears rpm or worry about belt slippage.


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## Azbrewer (Dec 4, 2015)

RJSakowski, thanks for the offer, however I should be getting a pack of 100 later on today.


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