The most commonly used lathe chuck including 3-jaw and 4-jaw. What’s the difference between the four jaw chuck and three jaw chuck?
1.Construction and motion
Three jaw chuck refers to self-centering chuck, its jaws are interconnected via a scroll gear and move at the same time, while jaws on four-jaw chucks move independently and require operators to center the workpiece.
2. Uses
Three-jaw chuck is the best option for holding circular or hexagonal cross-sections, while 4 jaw chuck is primarily useful for gripping square or octagon block.
3. Setting time
Four jaw chucks often take longer to set up but can do more than a 3 jaw chuck.
4. Accuracy
3-jaw chuck with an accuracy level of around 0.010 and the accuracy level of 4-jaw chuck is between 0 and 0.001.
5. Number of holes
The three jaw chuck has only one hole for the chuck wrench or key to tighten or release the gripping, but a four jaw chuck has four holes for controlling each jaw, one at a time.
6. Depth of cut
In four-jaw chuck, the produced depth of cut is higher than that in three jaw chucks.
7. Workpiece weight
Heavier stock can be turned in 4 jaw chuck but can’t in three-jaw.
8. Gripping power
The gripping power of four jaw chuck is larger than 3 jaws.
9. Function
Eccentric turning is possible when the part is fixed in 4 jaw chuck, which can’t be done in 3 jaw chuck.