3.1″ 4-Jaw Chuck
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 up to 2-3/4″ with the jaws reversed. A smaller 2.5″ diameter chuck is also available.
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 (14 mm x 1 mm).
*Please note that 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.
Jaw Options
- 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 box below - Soft (not hardened or machined) steel jaws are also available when you build your own chuck.
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| 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 in 2.5″ diameter) |
| Chuck Body Material | 12L14 Steel |
| Chuck Jaws Material | 12L14 Case Hardened Steel |
| Part No. | Description | Quantity |
|---|---|---|
| 10761 | 3.1″ 4 Jaw Chuck Body 3/4-16 Thread *Not sold separately | 1 |
| 10402 | 3.1″ Chuck Scroll *Not sold separately | 1 |
| 10413 | Chuck Retainer Ring | 1 |
| 11771 | 4 Jaw Chuck Jaw – Self Centering* | 4 |
| 40580 | Tommy Bar | 2 |
*Because chuck jaws are factory ground to precisely match each chuck body you must send your chuck back to us to be fitted with new jaws. Please contact us for instructions on how to return your chuck.
Click the P/N below to download a zipped version of the IGS 3D CAD file. You will need to extract the zip file before viewing the IGS file.
1076 4-Jaw Chuck 3D IGS model
You need an IGS viewer to view .igs files. CLICK HERE to download a FREE IGS viewer.
Related products
- Ductile plating with columnar structure
- Harder than any other nickel-based coating
- Coating uniformity that eliminates post-plate grinding (or burnishing)
- Wear properties overall superior to hard chromium
- Hardness (68-72 Rc)
- Low coefficient of friction (.044) Teflon™ is .04
- Uniform coating thickness up to .004”
- Accepts dry film lubricants
- 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 box below
- Soft (not hardened or machined) steel jaws are also available when you build your own chuck.
- 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 box below
- Soft (not hardened or machined) steel jaws are also available when you build your own chuck.
- 1 1/4" x 1" steel dowel pin that is used to adjust the jaws during installation and to chuck up on while boring and turning the jaws
- 1 1/8" hex key for tightening the 4-40 x 3/8" jaw mounting screws
- 2 spindle or "Tommy" bars for loosening and tightening the chuck


3.1″ 4-Jaw Chuck – Electroless Nickel Coated
This chuck is identical to P/N 1076 except for an Electroless Nickel coating that has been applied to help prevent wear and corrosion. This special coating has been applied to all external and internal surfaces of the chuck (except for chuck jaws), significantly improving the life of the chuck. This chuck also opens and closes more smoothly due to the lubrication properties of Nickel-Teflon.
Some of our customers have been wondering how to tell the difference between our standard chucks and those that have the Electroless Nickel coating. Standard chucks have darker markings than the coated chucks (See Figure 1. Click on photo to view a larger image).
[caption id="attachment_4231" align="aligncenter" width="300"]
Figure 1—Examples: (Left) 1040 3-Jaw Chuck (3.1″), (Right) 1040C Electroless Nickel Coated 3-Jaw Chuck (3.1″).[/caption]
Here, at Sherline Products, each of our chucks is laser engraved with a company mark, chuck size, and jaw location. During the laser marking process the laser removes a bit of the surface and darkens the material below (Figure 1, left). When chucks are sent out to receive the Nickel-Teflon finish the coating process changes the dark engraved markings to a noticeably lighter finish (Figure 1, right).
There is also a subtle change in the color of the chuck, but in the absence of being able to compare them side by side, the most evident way to tell whether you have a coated chuck, or not, is to check the color of the laser markings.


3.1″ 4-Jaw Chuck – ER-16
For use on the ER-16 headstock only Not for use on the standard headstock that comes on all Sherline Machines
Sherline offers their 3.1" 4-jaw self-centering chucks with a 22 x 1.5 mm threaded hole for use on Sherline's optional ER-16 spindle nose. They can also be used with certain other ER-16 spindles that use the 22 x 1.5mm thread for the collet nut.
Self-centering chucks offer a quick and convenient way to hold a work piece while it is turned on the lathe. A chuck can also be clamped to a mill table to hold a part for milling. Sherline manufactures our own chucks to a high degree of precision on CNC machines. The jaws are ground and fitted to each chuck by skilled technicians to assure maximum accuracy. Runout is specified to be .003" or less at the chuck jaws.
NOTE: The chuck should not be used in applications where spindle speed exceeds 3000 RPM. If purchasing any of these chucks for use on a non-Sherline ER-16 spindle, confirm that the spindle nose thread is 22 x 1.5 mm before purchasing. The Sherline chuck has a collar that is machined flat at the back to seat against the face of the Sherline ER-16 spindle. This may not be compatible with some non-Sherline ER-16 collet adapters or industrial tool holders. Runout accuracy cannot be guaranteed unless used with a Sherline spindle.
Jaw Options

3.1″ 4-Jaw Chuck with Pie Jaws
Includes a steel dowel pin, hex key, and 2 tommy bars, not pictured.
This chuck features a Electroless Nickel coated chuck body for durability and rust resistance.
Included with the chuck and jaws:Because the jaws are meant to be bored to size for particular jobs, eventually they will need to be replaced. The replacement set P/N 1143-4P can be installed on your existing 1076C Electroless Nickel coated chuck body and master jaws. They are NOT intended for use on the standard 1076 chuck body.
NOTE: These jaws are designed to be used ONLY on our Electroless Nickel coated chuck P/N 1076C, and master jaws are custom fitted to each body, so master jaws (11445-P) are not available for purchase separately.
Why pie-shaped jaws?First developed by watch and clock makers, chucks with pie-shaped jaws offer two main advantages. Boring the unhardened jaws to hold a particular diameter part means that instead of gripping the part at only three or four tiny contact points, they grip the part all the way around its diameter. This increased gripping area allows for much less clamping pressure and less chance of deforming a gear or other delicate part held in the chuck. In addition, because the face is bored to an exact and consistent depth, placing additional parts in the chuck for turning or milling means each part surface is held at exactly the same depth as the previous parts, saving setup time.
Use on ornamental turning lathesWe decided to make pie jaws for our four-jaw self-centering chuck after a request by David Lindow, the owner of Lindow Machine Works, Maker of Modern Rose Engine Lathes, (https://lindowmachineworks.com/lindow-rose-engine-menu/). Ornamental turners need a chuck that can firmly grip wooden stock without damaging the surface. In addition to David’s request, we had also received several requests from our horological customers who were looking for a chuck similar to the Swiss-made watchmaker's scroll chuck. We designed our pie jaws in both form and function after the Swiss chucks.
How to Distinguish between Standard Chucks and Coated ChucksSome of our customers have been wondering how to tell the difference between our standard chucks and those that have the Electroless Nickel coating. Standard chucks have darker markings than the coated chucks (See Figure 1. Click on photo to view a larger image).
[caption id="attachment_4231" align="aligncenter" width="300"]
Figure 1—Examples: (Left) 1040 3-Jaw Chuck (3.1″), (Right) 1040C Electroless Nickel Coated 3-Jaw Chuck (3.1″).[/caption]
Here, at Sherline Products, each of our chucks is laser engraved with a company mark, chuck size, and jaw location. During the laser marking process the laser removes a bit of the surface and darkens the material below (Figure 1, left). When chucks are sent out to receive the Nickel-Teflon finish the coating process changes the dark engraved markings to a noticeably lighter finish (Figure 1, right).
There is also a subtle change in the color of the chuck, but in the absence of being able to compare them side by side, the most evident way to tell whether you have a coated chuck, or not, is to check the color of the laser markings.


Build Your Own Chuck
3-Jaw Self-Centering chucks 4-Jaw Self-Centering chucks 4-Jaw Independent chucks Various chuck jaws
Lead time for custom-built chucks is 4-5 business days.




