# How Much Run Out Is Acceptable On Drill Chuck



## Swerdk (Jul 31, 2015)

when testing a drill chuck on a lathe,how do you judge acceptable run out?      I am new to this so I want to see if my Chinese drill chuck is worth keeping.    I have not tested it yet but it seems that  people are happy if run out is <.003   Is this correct?


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## wrmiller (Jul 31, 2015)

I personally would consider 3 thou acceptable for a Chinese drill chuck.


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## Swerdk (Jul 31, 2015)

But what is acceptable for a rohn or albretch (sp?)




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## JimDawson (Aug 1, 2015)

Swerdk said:


> But what is acceptable for a rohn or albretch (sp?)



I guess I would want a little more accuracy out of a Rohn or Albrecht. I would expect near 0, but the arbor has a lot to do with this too.

I'm going to catch he!! for this, but the easiest way to dial in a drill chuck is with a ground pin in the jaws and smack the chuck body with a dead blow hammer to indicate it in.  Works in drill presses, lathes and mills.  No, it won't hurt your spindle.
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## Swerdk (Aug 1, 2015)

Interesting.  What are you using for the pin


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## JimDawson (Aug 1, 2015)

I should have been more clear, you smack the body of the chuck with the dead blow, not the pin.  Any dowel pin or similar will work.

I edited my post above.


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## tomh (Aug 1, 2015)

Don't get to concerned about your drill chuck's  accuracy,  it will be no better  the bit  that you use.  Just remember that a drill chuck / bit  is basically  a roughing tool.


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## chips&more (Aug 1, 2015)

I have seen brand new name brand chucks have >0.005” run out. The one chuck I usually grab has been with me for decades and has <0.001” run out. And I have spun a tap in it more than once and it still runs true. Never had to hit it with any hammer either. I don’t think the best name brand chuck is going to make you happy every time. Because a lot of USA manufactures are Importing now.  I think, if you just find a good chuck from under test, hang on to it…Dave.


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## hermetic (Aug 1, 2015)

I agree dave! to the OP swerdk, dont sweat about accuracy, get on and make what you want to make, and if you find you cannot make something because the chuck is not accurate enough, buy a better chuck! Seriously, I had a 3 jaw  lathe chuck  that was .017 out, but it was the only three jaw I had to fit that lathe (L0 taper) You could dial it in to about .007 with a bit of messing and tapping, but it made everything I made on the lathe, and it all worked and was good enough! When a new chuck came along with about .003 to 004 runout I bought it, it is more repeatable, does not require so much messing with, but I don't make any more or any less components now with the new chuck than I did with the old innacurate one, are you getting my drift? all three jaw self centering chucks have run out, the most accurate chuck you have is a 4 jaw! You can expect better than 004" concentricity with a Rohm or an Albrecht type chuck, but you will not get .000" unless you are phenominally lucky, engineers work to tolerances, not dead on sizes!
Phil


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## HighWall (Aug 1, 2015)

My Glacern 1/2" keyless chuck is .0015 with a dowel pin.  First time I indicated it, it was with a 1/2" drill bit.  It was out by .005, which made me not so happy.  I repeated the test with the dowel pin and got a more accurate reading.


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## hermetic (Aug 2, 2015)

So you can't drill holes with a dowel pin, but you have gone straight to the conclusion that the problem is the drill! absolute right thing to do, then check your drill shank for burrs and skidmarks, hone them down, and try again, check the chuck jaws, and even strip clean and lube the chuck, you will get nearer all the time, but what you are getting nearer to is the original tolerance to which the chuck was made, not .000! the more time you take over checking the set up before you machine, the more accuracy you get


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## Swerdk (Aug 2, 2015)

Thank you everybody for your replies 
Lots of good ideas


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