# Tell Me The Advantages of 6 Jaw Lathe Chuck



## Ulma Doctor (Sep 2, 2017)

i'm toying with the idea of purchasing a 6 jaw chuck for a lathe i own.

if anyone can state the virtues or the disadvantages in their view, i'd sure like to hear them.

i have already accepted that this item is not necessarily a must have, i have gone to this point without.

thanks in advance for any opinion!


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## bfd (Sep 2, 2017)

th only advantage that I know about is less distortion on thin wall  tubing and thin parts. there may be other opinions bill


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## bfd (Sep 2, 2017)

hey shouldn't you be out in the shop playing not at home on the computer oh well , the second advantage is parting off a tough material a six jaw does not have the space between jaws like a 3 jaw chuck so the part has less places to go if the chips stick in between the parting tool and the material. in a three jaw the part has lots of room to move to and will runout as you are parting the 6 jaw would hold the part more firm bill


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## mksj (Sep 2, 2017)

Another advantage is the ability to hold very small stock because the chuck jaws tend to be narrower at the tips, but pretty much moot if you use any kind of collet system. The look neat on your lathe.

There are also a few negatives to consider:
1. The 6J tend to fowl much easier with chips and swarf, a real pain to clean.
2. If stock is not perfectly round, you will only be holding the stock with 2J and it will tend to move. Also jaw alignment can be an issue,  in particular with two piece jaws.
3. They are heavier so they are usually more limited in top speed (usually not an issue in our setting, and one can also go to a forged chuck $$$)
4. Reversing the jaws for ID/OD work is very time consuming (PTA)
5. My understanding is that for anything other than thin wall tubing, a 3J and for that matter 4J will hold the stock more securely
6. If you use soft jaws, from what I have read they are not used on 6J
7. Cost, can be significantly more.

So fairly limited advantages unless you do a lot of work with thin wall tubing. I do not know how a collet system would stack up against a 6J for tubing under 1", I would think that an ER-40 system would work well, 5C less so. If you are looking for another chuck that gives a bit of the best of both wolds you might consider a Bison combo. I have the 8", one can easily hold stock down to 0.2", handles uneven stock, and seems to hold stock more securely than my 3J.  The scroll repeats to about +/-0.001" and you can tweak the independent jaws down to get the run out to near zip. I use it the most second to my 5C collet setup. A 4J on thin wall tubing, not sure that it would be much better than a 3J.


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## dlane (Sep 2, 2017)

But they look cool , and dangerous


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## darkzero (Sep 3, 2017)

I don't know but they sure are purdy!

Chuck porn! 

(There's much sexier looking ones out there too!)


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## darkzero (Sep 3, 2017)

There's more disadvantages to a 6j than there are advantages. But when you need or like those advantages they're invaluable. As said the main advantage of a 6-jaw chuck is the ability to hold thin wall work with much less deformation so it depends on the work you do. I got into machining cause I used to mod flashlights heavily. I would need to hold flashlight parts like bodies, tailcaps, heads, reflectors, etc. I remember the first time I tried to hold a small plastic reflector, they kept fly out of the 3j & I destroyed 5 of them before giving up. Some of the custom reflectors were quite pricey & some were hard to get. Had to resort to making custom collets/jigs to hold certain parts with a 3j. That got to be a PITA quick.

They say a 6j is a second op chuck & an adjustable 6j can be an alternative to collets. Not in the sense for safety for close up work (the jaws) but cause you can quickly chuck up a semi finished part pretty accurately & quickly. I have a ER40 chuck for may lathe but I pretty much never use it. It takes too long, my 6j is much quicker & pretty damn accurate. Of course a 5C setup with a collet closer would be quickest which I don't have. Collets also are not an advantage for me cause I don't always work with nominal size parts. I only use collets when I'm really scared for my knuckles. More jaws equals more pain, trust me I know!

I find with the 6j I can chuck up shorter parts more accurately & quicker than a 3j, with more jaws it much easier to chuck up a short part straight (axially) without having to use a pusher tool like a ball bearing mounted on a bar or indicate. With that said, a 4j should hold thin wall parts better than a 3j. But yes & no, 4j independent is the most popular but chances are you tend to deform a part more because each jaw is independent & you just naturally put more pressure on a part with each jaw. Now with a 4j scroll or combo chuck yes, they seem to be less popular though.

Some say a 6j holds better & some say they don't. More jaws doesn't necessarily mean more/better grip. In my experience it goes both ways. 6j will hold thin wall & smaller diameters better but with larger more solid work you can get slippage. I use a 3j or 4j when I really need to grab a hold of something tight, because they'll dig into the part better. With more jaws there's more surface area holding the part so a 6j does not dig in well, the force through the scroll is transferred through more jaws. But that's another advantage for me. I'm anal, I hate leaving jaw marks on parts & in many cases I can't as I have to chuck on a finished area.

I've had work slip in my 6j before, most of the time I can just crank down on it harder & be fine. I no longer do that cause it's not worth the added wear on it. That's when I use a 3j.

Some say a 6j does not grip well if the stock is not perfectly round. This is true in theory but it hasn't been a problem for me. I buy stock from a large metal supplier that i'm lucky to have locally, I rarely use stock that I scrounged somewhere. So pretty much all the stock I buy is cold rolled/extruded/ground, they come well rounded & are not beat up. Of course not perfectly round but again I've never had a problem.

Even though I don't work on flashlights much anymore these days, my 6j is still my primary chuck. I use it 80% of the time, followed by my 4j indie, then my 3j, & again collets have not been useful to me with the type of stuff I work on. Being so used to the 6j I can't live without it. When I got my new Bison 3j Set-Tru, I tried to use it as my primary chuck, I just couldn't, I found myself switching back to my 6j alot. I guess I'm just too used to using my 6j.

There's more disadvantages but my post is way too long already, plus I'm a 6j fan boy so I'll leave those "absurd negative disadvantages" for others to post. Haha

And my disclaimer: I'm just a hobby dude & not a machinist by trade. These are just my experiences & opinions, I may have no idea what I'm even talking about.


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## Doubleeboy (Sep 3, 2017)

I have found that my 6 Jaw does not hold as well as 3 jaw if item is less than perfectly round.  A 3 jaw will easily hold tight on a diameter that is a bit out of round,  sometimes bar stock does not hold tight enough for a roughing cut in the 6 jaw.  Its great for thin wall parts and soft parts but if I was just starting out and was looking for one chuck it would certainly be a 4 jaw first, collet chuck second, 3 jaw third and 6 jaw fourth.


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## Ulma Doctor (Sep 3, 2017)

great stuff guys!

i should have specified that i already have 5c collets, 3j and 4j chucks 

my intentions are for thin walled tubing work with the 6j.

i  really appreciate the input guys!!!


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## richl (Sep 3, 2017)

They are sexy!!! I do a fair bit of tubing work (tube bending, bike frames, architectural work, handrails and such)... yet I can not ever remember putting tubing in the lathe for turning... am I missing something.

I just finished up a project that used schedule 40 tubing, id 1 1/4" so I do have a number of scrap pieces laying around the shop looking for tooling projects to be used on...

So enlighten me... what am I missing?

Rich


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## kd4gij (Sep 3, 2017)

I knew Will would be along with great advise.


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## Silverbullet (Sep 3, 2017)

You can use 2jaws or 3jaws or 4 or 6 , if it has two piece jaws you can make soft jaws for odd shapes too. I have one and love mine even tho mines solid jaws. Really get a lot of doubters about them I for one have never had a problem with mine. And I have used it in some combinations to do different things. The only chuck I'd like to have is the two way four jaw independent and scroll combined . But there beyond my reach .


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## Bamban (Sep 3, 2017)

Mike,

Get a set thru 6J, you wont regret it. Love mine. When I am lazy to set up the spider finger clamp I use the 6 inch set thru 6J to thread the muzzle on AR barrels, never had slippage even on polished surface and no marring on surfaces.

On the 6 inch Gator I replaced the jack set screws with flange bolts so I can use a socket and a ratchet.

The 8 inch Bison sits naturally on the SBL 13, it was a little too big for the 1236. It over current the HY VFD when spun at max speed.


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## Ulma Doctor (Sep 3, 2017)

thanks you guys, i'm glad that i asked the question!!!
i'll be getting a new 6J chuck very soon


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## JPigg55 (Sep 4, 2017)

So let me understand this.
You're asking a bunch of tool junkies if you should buy another tool ???........ LMAO








Here's to the new acquisition !!!!


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## Ulma Doctor (Sep 4, 2017)

you have a very good point there JPigg!
here's mud in your eye!


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## Alan H. (Sep 4, 2017)

Ulma Doctor said:


> thanks you guys, i'm glad that i asked the question!!!
> i'll be getting a new 6J chuck very soon



Mike, now that you have some excellent info from this thread, looks like its catalyzed a sizable opening of your wallet! 

Meanwhile one quick question for you for me to gain some perspective.   I noticed you have a 5C setup.  Is your desire for a 6 jaw driven in part by work on thin wall tubing greater in OD than the 5C collet capacity? 

BTW, thanks for starting this thread - good insights shared here.


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## Ulma Doctor (Sep 4, 2017)

Alan H said:


> Mike, now that you have some excellent info from this thread, looks like its catalyzed a sizable opening of your wallet!
> Meanwhile one quick question for you for me to gain some perspective.   I noticed you have a 5C setup.  Is your desire for a 6 jaw driven in part by work on thin wall tubing greater in OD than the 5C collet capacity?
> BTW, thanks for starting this thread - good insights shared here.


Hi Alan,
thanks for reading and commenting.
yes Alan, i have 5c collets but the tubing will range from 1-1/2" to 3" in diameter
i suppose i could figure other ways of holding the work, but convenience may just take over to save valuable time.
i'll post pix when i get the chuck!


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## Alan H. (Sep 4, 2017)

Thanks Mike, makes sense.   

Looking forward to seeing what you end up with.


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## chips&more (Sep 4, 2017)

It’s gonna take you twice as long to take the jaws in and out as would a three jaw.


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## Doubleeboy (Sep 4, 2017)

Ulma Doctor said:


> Hi Alan,
> thanks for reading and commenting.
> yes Alan, i have 5c collets but the tubing will range from 1-1/2" to 3" in diameter
> i suppose i could figure other ways of holding the work, but convenience may just take over to save valuable time.
> i'll post pix when i get the chuck!



If you only have a few sizes between 1.5" and 3" you might want pot chucks for your 5 C.   Sometimes you can snag prebored ones pretty cheap on ebay.  Might save you some $ compared to buying a chuck.


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## Ulma Doctor (Sep 4, 2017)

Doubleeboy said:


> If you only have a few sizes between 1.5" and 3" you might want pot chucks for your 5 C.   Sometimes you can snag prebored ones pretty cheap on ebay.  Might save you some $ compared to buying a chuck.


great idea thank you for the tip!


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## kd4gij (Sep 4, 2017)

Ulma Doctor said:


> i'm toying with the idea of purchasing a 6 jaw chuck for a lathe i own.
> 
> if anyone can state the virtues or the disadvantages in their view, i'd sure like to hear them.
> 
> ...




 Why question it.  If it is a tool you don't have then it is a tool you need


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## ariscats (Sep 14, 2017)

Ulma Doctor said:


> great idea thank you for the tip!


If you take three jaws out don't you have a three jaw chuck?
Ariscats


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