# best chuck for a 12 inch lathe



## Coalman

I am new at this and I just bought a 12 inch Craftsman (atlas) That came with a 5 in 3 jaw chuck with only one set of jaws. The jaws only open to about 2 3/4 inches I am looking at getting another chuck to do larger pieces. What would the largest chuck That I could use safely and also that would not stress the machine ( was at grizzly today and salesman said anything bigger than a 6 would ruin the bearings?) also 3 or 4 jaw ?Thanks in advance Kevin


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## Ray C

These days, a new 12" lathe will come with 6 and 8" chucks.   You need to be mindful that opening the jaws a great distance might lead to an unsafe condition.  A jaw can come out and hit you and the workpiece might be soon to follow.  Also the jaw might not clear the ways.   Also note that most jaws are reversible and can be flipped the other way to grab the inside of a large diameter pipe for-example.

I tend to think that if you have a lower-powered motor a smaller chuck would be better.

Many 3 jaw chucks are "universal" meaning, the jaws move in unison and you don't need to worry about centering the work because it's done automatically by the chuck.  Often times, the 3 jaw chucks are not perfect and cannot perfectly center a piece.  Most 4 jaw chucks are "independent".  Each jaw must be individually set to evenly clamp the workpiece.  It's a manual process that can center a workpiece perfectly.  There are times when you want to spin a piece offset and that can only be done with an independent chuck.  Also, if you have a thinwall tube to hold, it's better to have 4 jaws (or even 6) to distribute the clamping force.

There are times when a 3 jaw is the only way to go -for example, clamping a piece of triangular or hexagon shaft.

A common combination for folks with lathes that size is to utilize both a 6" independent and 8" universal.

EDIT:  Fixed a sentence.


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## Bill Gruby

"There are times when only a 3 Jaw will work, like when holding hexagonal stock". Not quite true Ray, they do still make 6 jawed chucks. :lmao:

"Billy G"


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## Ray C

Yeah, and they look really cool -kinda like a piece of aircraft equipment.  -Would love to have one for bragging rights but, I'm not sure I'd ever use it.  -When I win the lottery!

Seriously though... Do you know if those things are usually independent or universal?




Bill Gruby said:


> "There are times when only a 3 Jaw will work, like when holding hexagonal stock". Not quite true Ray, they do still make 6 jawed chucks. :lmao:
> 
> "Billy G"


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## Bill Gruby

They are scroll chucks Ray.  That means all jaws move at once. That narrow the choice down, right? :lmao:

 "Billy G" )


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## Ray C

-And glad of it!  Can't imagine trying to describe to someone how to center a piece with 6 independent jaws.  -Yikes.




Bill Gruby said:


> They are scroll chucks Ray.  That means all jaws move at once. That narrow the choice down, right? :lmao:
> 
> "Billy G" )


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## Bill Gruby

Center the piece with 3 of the jaws, every other one, then snug the other three to hold. But then this is hypothetical huh, since they don't exist. I now turn this thread back over to it's owner. My apologies to Coalman.

"Billy G"


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## irishwoodsman

Coalman said:


> I am new at this and I just bought a 12 inch Craftsman (atlas) That came with a 5 in 3 jaw chuck with only one set of jaws. The jaws only open to about 2 3/4 inches I am looking at getting another chuck to do larger pieces. What would the largest chuck That I could use safely and also that would not stress the machine ( was at grizzly today and salesman said anything bigger than a 6 would ruin the bearings?) also 3 or 4 jaw ?Thanks in advance Kevin


 i like the 4 jaw chuck to me its easier to center your work piece but they have scroll chucks that are self centering but since your new at this i would go to a 4 jaw once you learn how to center it good then you can move on to better chucks i have a 11'' sheldon and a 6 is what i got on mine, you might try turning your jaws around to grasp bigger projects and even useing a face plate and drive dogs and use centers on each end, i hope i'm explaining this right but there is more members to help too if i'm not)mac


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## Bill Gruby

I agree Irish, once you get adjusting down pat you will love the 4 jaw.

 "Billy G"

 Welcome back my friend.


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## darkzero

I've have an import 12x36 & I love my 6.25" 6-jaw Set Tru. I sold the 8" 4-jaw that came with the lathe & replaced it with a Fuerda 8" 4-jaw. The 6" 3-jaw that with the lathe is not as bad as the 4-jaw that came with the lathe so I kept it & use it when I need to sand/polish a bunch of stuff or to hold smaller stuff. I wouldn't want the 4-jaw to be smaller than 8" but I wouldn't want my 3 or 6 jaw chucks to be any bigger than 6.25" which I use the most. I love the 6-jaw Bison chucks but they can't hold smaller diameters like down to 3/16" or so.


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## irishwoodsman

Bill Gruby said:


> I agree Irish, once you get adjusting down pat you will love the 4 jaw.
> 
> "Billy G"
> 
> Welcome back my friend.


  thank you BILLY G it good to be back)  mac


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## ML_Woy

Coalman said:


> I am new at this and I just bought a 12 inch Craftsman (atlas) That came with a 5 in 3 jaw chuck with only one set of jaws. The jaws only open to about 2 3/4 inches I am looking at getting another chuck to do larger pieces. What would the largest chuck That I could use safely and also that would not stress the machine ( was at grizzly today and salesman said anything bigger than a 6 would ruin the bearings?) also 3 or 4 jaw ?Thanks in advance Kevin



I have a Craftsman 12" Lathe, 1943 vintage and I recently purchased a new three jaw chuck from Enco. I had the same three jaw chuck you described when I purchased my machine and I was not happy with it. Well to shorten the story, ENCO ran a special and I purchased their "Three Jaw "Set Tru" Scroll Chuck model # 272-5000 that lists for $327.00 and then  purchased their Part # 274.5090, 6.25" back plate for $188.46. Now the chuck was on sale and I don't remember how much savings their was, but that is not important.

When I received the two items I found out that the back plate did not match up to the face plate, but the price of the chuck made it  possible for me to turn the face plate down to fit, I had to drill six holes to mount the face plate to the chuck but it has turned out to be a great combination. I really love the chuck and would recommend the pair to anyone with a Craftsman 12" lathe. It has made a big difference in the quality of my work.

If your budget can handle these item consider them.


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## irishwoodsman

ML_Woy said:


> I have a Craftsman 12" Lathe, 1943 vintage and I recently purchased a new three jaw chuck from Enco. I had the same three jaw chuck you described when I purchased my machine and I was not happy with it. Well to shorten the story, ENCO ran a special and I purchased their "Three Jaw "Set Tru" Scroll Chuck model # 272-5000 that lists for $327.00 and then  purchased their Part # 274.5090, 6.25" back plate for $188.46. Now the chuck was on sale and I don't remember how much savings their was, but that is not important.
> 
> When I received the two items I found out that the back plate did not match up to the face plate, but the price of the chuck made it  possible for me to turn the face plate down to fit, I had to drill six holes to mount the face plate to the chuck but it has turned out to be a great combination. I really love the chuck and would recommend the pair to anyone with a Craftsman 12" lathe. It has made a big difference in the quality of my work.
> 
> If your budget can handle these item consider them.


 useally the backing plates come to where you turn it to fit the chuck kinda like training excersize for you i think:thinking:  mac


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## ML_Woy

That may be the case, but ENCO did not have a plate to match that chuck and  it had to be modified. The Backing Plate had three holes to mate the chuck and the chuck required six holes, it was also out of true for the spindle and had to be corrected. But for he price it was a real savings and well worth the modifications.


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## irishwoodsman

ML_Woy said:


> That may be the case, but ENCO did not have a plate to match that chuck and  it had to be modified. The Backing Plate had three holes to mate the chuck and the chuck required six holes, it was also out of true for the spindle and had to be corrected. But for he price it was a real savings and well worth the modifications.


 oh yea i found out along time ago if you can do mods your going to save your wallet)  mac


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## kd4gij

I have an 8" 3 jaw chuck with 2 pice jaws on my Craftsman 12x52 Been fine for 5 years now also have an 8" 4 jaw for it


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## 12bolts

Ray C said:


> ....   Also note that most jaws are reversible and can be flipped the other way to grab the inside of a large diameter pipe for-example.....



Should also point out that 3 jaw universal chucks do not have jaws that can be simply flipped around. The drive teeth on the jaws are cut radialy to suit the scroll.
Reversible jaws need to be unbolted from the carrier and turned. Alternatively the chuck may be supplied with a 2nd set of reversed jaws.

Cheers Phil


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## KySawdust

ML_Woy said:


> I have a Craftsman 12" Lathe, 1943 vintage and I recently purchased a new three jaw chuck from Enco. I had the same three jaw chuck you described when I purchased my machine and I was not happy with it. Well to shorten the story, ENCO ran a special and I purchased their "Three Jaw "Set Tru" Scroll Chuck model # 272-5000 that lists for $327.00 and then  purchased their Part # 274.5090, 6.25" back plate for $188.46. Now the chuck was on sale and I don't remember how much savings their was, but that is not important.



Can someone explain why a 6.25" round plate with a few holes in sells for so much? $188 sounds like a lot for a backplate but i have seen them priced like this as well  I am sure that I am missing something. Thanks!


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## george wilson

I have seen an older Southbend 6" 3 jaw chuck whose jaws were able to be turned around. That is the only such chuck I've seen,though. It would be handy if others made their jaws reversible. Not a great reduction in the strength of the jaw threads.


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## ML_Woy

KySawdust said:


> Can someone explain why a 6.25" round plate with a few holes in sells for so much? $188 sounds like a lot for a backplate but i have seen them priced like this as well  I am sure that I am missing something. Thanks!



Well by time the guy who made it in Poland sold it for $25.00 to the exporter in Poland and he shipped it to the USA and sold it for $50.00 to cover his cost and profit, and the importer sold it to ENCO for $100.00 for his handling, ENCO sells it to me for $188.00 and makes their profit. Remember what a pound of flour sells in the store and what the farmer gets for the wheat. Same thing. Sad thing is in the early "60's" you could have bought it for $60.00 with the $1.00 per hour you were being paid to pump gas in that service station selling $.25 per gallon gas.


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## Ray C

-And once you get your expensive round metal plate, you need to spend a good bit of time making it perfectly fit your lathe and chuck.

For screw-on types, the work is not as complicated because there's not much you can do but D1-x types need a good bit of work. When I purchased several new backs, I was amazed at how far off things were. The nose tapers weren't even close -or all that round as a matter of fact. I reset the geometry and surface ground first the spindle side then lightly went over the chuck side. After getting the back's taper to match the spindle nose taper, I cut it just deep enough to allow the backs to come into contact just right.

I knew that my chucks were square because I'm the original owner and surfaced them when I got them. Anyhow, after tuning-up all the D1 backs, all of my chucks re-mount either dead-on or within a half thou.




KySawdust said:


> Can someone explain why a 6.25" round plate with a few holes in sells for so much? $188 sounds like a lot for a backplate but i have seen them priced like this as well I am sure that I am missing something. Thanks!


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## george wilson

An 8" chuck is fine for a 12" Sears lathe. I had an 8"4 jaw chuck for mine. It won't ruin the angular ball bearings in the lathe's spindle. Indeed,the front wheel bearings in my old 1950 Chevy were not as large as the tapered roller bearings in a 12" Sears Atlas lathe(my first lathe). The important considerations are: Will the jaws clear the ways enough to crank them out sufficiently to use the chuck's full capacity? On a Sears lathe,you may or may not be able to have the power or rigidity to turn a real large piece of steel anyway. Brass or aluminum will likely be workable. I had lots of trouble with my 12" Sears lathe being rigid enough to take a decent cut. The bed also warped under load during cuts,causing it to not turn accurately.

Sears advertised .001" accuracy ONE INCH from the chuck. And,that was about right unless I babied my cuts along,taking a lot more time than should have been necessary to make something. My subsequent Jet 10" x 24" bench lathe was SO much better it was a revelation.


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## kd4gij

Here is an 8" chuck on my 12" craftsman 101.07403


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## rafe

I'd definitely recommend a 4 jaw (partially because you have a 3 jaw) 6" would likely be big enough not sure if the 8 would be too big to gain much over the 6. You can really dial in a 4jaw for accuracy ove a 3jaw. I picked up a used skinner 8" for my 14 1/2" online(E-bay) and had to machine a back plate that had the correct thread on it (shout out for backplate to tools4cheap) and I could not be more happy with the set-up. If you are patient you will find a 4jaw for that lathe for a reasonably investment. The independents are reversable, the scrolls are not unless they have 2 sets of jaws or bolt on (2piece) jaws ...I think that is an accurate statement


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## kd4gij

For a 4 jaw I would go with 8in for shure.


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## projectnut

The real advantage of a 4 jaw chuck is that the work can be removed repositioned and recentered.  Since each of the jaws moves independently all you need is a good dial indicator to adjust the work to well within .001".  Keep in mind there are several different styles of 3 and 4 jaw chucks.  I have 2, 8" chucks that are worlds apart.  The smaller one has a body only about 3" deep and is open on the back.  It weighs about 20 lbs.  The second one is nearly 6" deep and is totally enclosed on the back.  It weighs nearly 50 lbs.

A 3 jaw chuck on the other hand has a typical run out of .002" to .003".  In the commercial machining world they aren't considered to be precision chucks.  They're typically used where all operations can be done with a single setup or where the finished product is parted from the original stock.

As far as how wide the jaws are supposed to be opened the rule of thumb is that they should not extend beyond the chuck body more than 3/4".   On chucks with jaws less than 1 1/2" long only half the length of the jaws should extend beyond the body.  The reason for keeping the larger jaws to within 3/4" is safety for the operator.  On the smaller chucks it's to make sure enough teeth on the jaw are engaged to the scroll to provide sufficient gripping power.


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## Steve M

projectnut said:


> The real advantage of a 4 jaw chuck is that the work can be removed repositioned and recentered.  Since each of the jaws moves independently all you need is a good dial indicator to adjust the work to well within .001".  Keep in mind there are several different styles of 3 and 4 jaw chucks.  I have 2, 8" chucks that are worlds apart.  The smaller one has a body only about 3" deep and is open on the back.  It weighs about 20 lbs.  The second one is nearly 6" deep and is totally enclosed on the back.  It weighs nearly 50 lbs.
> 
> A 3 jaw chuck on the other hand has a typical run out of .002" to .003".  In the commercial machining world they aren't considered to be precision chucks.  They're typically used where all operations can be done with a single setup or where the finished product is parted from the original stock.
> 
> As far as how wide the jaws are supposed to be opened the rule of thumb is that they should not extend beyond the chuck body more than 3/4".   On chucks with jaws less than 1 1/2" long only half the length of the jaws should extend beyond the body.  The reason for keeping the larger jaws to within 3/4" is safety for the operator.  On the smaller chucks it's to make sure enough teeth on the jaw are engaged to the scroll to provide sufficient gripping power.




Was searching for exactly this info.  Just bought a Smithy import 12x37 and am in the process of working out the kinks.  The three jaw chuck seems to have about 0.0015 +/- runout using a brand new piece of 0.875" drill steel.  I checked for roundness with a mike as best I could, getting no more than 0.0002' variation (operator error?) and chucked it up.  When I take a light cut, I get 0.0005 - 0.001 runout on the turned part.  Seems like the out of roundness should equal that of the chuck, not sure why it is less.  Got similar results with the  mike.   Haven't tried the four jaw yet.  Was having some surface finish issues turning CRS - not there with the drill steel just as I expected.


Steve in Central TX


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## rgray

Steve M said:


> Was searching for exactly this info.  Just bought a Smithy import 12x37 and am in the process of working out the kinks.  The three jaw chuck seems to have about 0.0015 +/- runout using a brand new piece of 0.875" drill steel.  I checked for roundness with a mike as best I could, getting no more than 0.0002' variation (operator error?) and chucked it up.  When I take a light cut, I get 0.0005 - 0.001 runout on the turned part.  Seems like the out of roundness should equal that of the chuck, not sure why it is less.  Got similar results with the  mike.   Haven't tried the four jaw yet.  Was having some surface finish issues turning CRS - not there with the drill steel just as I expected.
> 
> 
> Steve in Central TX




.0015 on a 3 jaw is awesome. Wise mine were that good. Once you cut a piece you should have 0 run out though. As long as the cut compleatly "cleaned" for lack of a better discription...left no spots uncut....even if you had .003 TIR it would be 0 after the cut. That's why once you cut it round in your 3 jaw you don't want to remove it until it's done. Even if you mark it you may not get it back in to the same location and then it will have run out.

You may want to make a test bar by turning a piece of that drill rod between centers. It may be very round but not quite straight.


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## george wilson

I will say that the 8" chuck I bought for my 12" Sears lathe was made FOR that lathe. It was lighter than the 8" chuck shown just above. Only about 2" deep,with integral threads to screw on,and had a hollow casting on the back side that followed the contour of the parts. Probably nearly half the weight of an 8" chuck with added back plate.

I still don't think an 8" chuck would ruin a lathe with angular bearings. Now,bronze bearings on a very old model are a different case. I am not a student of early Atlas lathes,so I do not know if they had plain bronze bearings or not. Of course,old South Bend 9" lathes had the WORST possible setup: Cast iron bearings that were INTEGRAL with the headstock(As do most Myford lathes,except on SOME of the very last models). When those bearings wore,you were in trouble! Only some fancy line boring and re lining with bronze could fix them. Probably beyond the ability of most home shops. I WOULD recommend lighter chucks for such lathes. And,OIL the spindle bearings every time you use them,too!!

By the way: I always custom fit my back plates and true them up when ever I fit a new chuck.


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