Three- vs. Four-Jaw Lathe Chucks

CNC & Machining Education Workshop
Three- vs. Four-Jaw Lathe Chucks

Three-jaw chucks, of the same general type used to hold bits in most power drills, are also common equipment on metalworking lathes.  Though it is not necessarily so, three-jaw chucks are so commonly of the self-centering variety, in which the jaws are not independently adjustable, that “self-centering” is generally assumed from the term “three-jaw chuck.”

But there are distinct advantages to using a four-jaw chuck (which is generally assumed, contrariwise, to have independently-adjustable jaws), and though a three-jaw chuck is nice to have for convenience and for use with hexagonal stock, most machinists find the four-jaw chuck to be more versatile and useful in the long term.

This table is adapted from a list by Bruce Simpson, as quoted on Frank Hoose’s excellent lathe-work site.

16 thoughts on “Three- vs. Four-Jaw Lathe Chucks

  1. Piotr Wnek says:

    Actually you can buy 4 and 6 jaw self-centering lathe chucks, this is nothing new. More info on BISON-BIAL site. And 3-jaw version can also achieve high precision, expensive but possible.

  2. Jeff Del Papa says:

    There are 4 jaw scroll (what the trade calls a self centering) chucks.  Most wood lathes come with them.

    For handling thin tube, there are 6 jaw chucks, which hold at lower pressures.

    Scroll chucks tend to hold the same centering for pieces that are the same diameter.  That leads to the “Set-Tru” chuck – its a regular scroll chuck, with the ability to move it around relative to the spindle center.  It makes for fast centering when doing repetitive work. 

  3. Ryan Turner says:

    For precision work on a metal lathe you generally see only 4 jaw independent and 6 jaw chucks.

    If you are going to spend the cash on a decent self centering chuck it might as well have six jaws because it wont be much more than a 3 or 4 jaw and they don’t mar thin tube and soft materials as badly. Any aluminium surface finish gets chewed up pretty badly by a 3-jaw.

    As well, generally only companies who actually know what they are doing make six jaw chucks so you won’t get trash.

    1. Bob Darlington says:

      Yah, with the work I’ve done in precision machining you’re either using a 6 jaw chuck to lessen the deformation on the material, or you’re in a collet.  Not so much the 3 jaw, but they do have their use if precision isn’t a big deal.

    2. Piotr Wnek says:

      You have marks on aluminium or copper because you use hard jaws, for
      soft metal you need to use soft jaws. And precision of 3-jaw can be
      0.005mm (this is like 0.0001 inch ?).

      6-jaw chuck is used for thin wall materials (better load distribution). Many people forget about basics, when we use hard and soft tools.

  4. John Morse says:

    I’ve made a square block using a 4-jaw.  For practical use though, the 3-jaw and the collet holder are the ones that stay on the machine.

  5. Lathe Chuck says:

    Great info!  I love Make, and it’s great to see some lathe Chucks getting some love on here too!  Very cool!

  6. Bob Warfield says:

    If you’d like to compare and contrast the whole range of lathe workholding approaches, I’ve made up a table that might be helpful:

    http://www.cnccookbook.com/MTLatheHolding.htm

    Best Regards,

    Bob Warfield
    http://www.cnccookbook.com

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I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and makezine.com. My work has also appeared in ReadyMade, c't – Magazin für Computertechnik, and The Wall Street Journal.

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