3.1" 4-Jaw Self-Centering Chuck
Product #: 1076/1034
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This chuck combines the ease-of-use advantages of the 3-jaw chuck with some of the advantages of a 4-jaw chuck. It will automatically center square or round stock. (The stock must be accurately shaped for all four jaws to grip.) It will also grip thin-wall tubing in four places rather than three, which spreads out the load and allows more grip without crushing the tubing.
Turning the knurled portion of the outer diameter of the chuck scrolls all four jaws in unison. Included with the chuck are two Tommy bars for tightening and loosening the chuck.
Centering accuracy on self-centering chucks is to within a few thousandths of an inch. If perfect centering accuracy is required, see the section on 4-jaw independent jaw chucks.
This chuck will hold parts from 3/32″ in diameter up to 1-1/2″ with jaws in the normal position and from 1/4" up to 2-3/4″ with the jaws reversed. A smaller 2.5″ diameter chuck is also available as P/N 1075.
Chucks for Sherline and Other Lathes
The chuck is available in several spindle threads for use on Sherline (3/4-16) and other machines such as old Unimat lathes (14mm x 1mm).
NOTE: Chucks with a thread size other than 3/4″ x 16 are made to order and have a lead time of 5-7 business days.
- For those who have jobs where speed and ease of use are more important than maximum accuracy and want a chuck that is loose right from the start (No extra charge).
Add the note “loose jaws” to the “comments/shipping instructions” box when checking out.
- Soft (unhardened) steel jaws are also available upon request (No extra charge).
Add the note “soft jaws” to the “comments/shipping instructions” box when checking out.
- Interchangeable top jaws are also available.
- Chuck Diameter - 3.1″
- Jaw Capacity -
With jaws in normal position: 3/32″ (2mm) – 1-1/2″ (38mm)
With jaws in reverse position: 5/16″ (8mm) – 2-3/4″ (70mm)
- Through Hole Diameter - .687″ (17mm)
- Thread Size - 3/4-16 (other thread sizes available)
- Chuck Body Material - 12L14 Steel
- Chuck Jaws Material - 12L14 Case Hardened Steel
Removing a Stuck Chuck from the Spindle
Use one tommy bar in the hole in the spindle and another tommy bar in a hole in the chuck body to achieve enough leverage to unscrew the chuck (counter-clockwise) from the spindle thread. If the chuck becomes stuck on the spindle thread, put a tommy bar in the hole in the chuck body. Place a block of wood against the tommy bar where it enters the chuck. With a small mallet, give the block of wood a sharp tap, turning the chuck in a counter-clockwise direction. It should not be necessary to hold the spindle, as its inertia should be sufficient. (Don’t hit the tommy bar anywhere other than right where it enters the chuck or you could bend it.) This small but sharp force at the outer edge of the chuck should break the thread loose and the chuck can then be unscrewed by hand.
40580 - Spindle Bar
Download PDF 1075 Instructions
Because chuck jaws are facotry ground to precisely match each chuck body, replacement jaws cannot be bought either individually or as a set. If you need to replace the jaws you can give us a call or send us a message to set up returning your chuck for installation of new jaws.