Lathe machines are tools that spin blocks of material as abrasive or cutting tools are applied to the material. Often used to shape objects with rotational symmetry, lathes are used on wood, metal and other common construction materials. Lathe chucks are an essential part of any lathe machine as they are important in holding and clamping objects safely and securely in the lathe machine. There are four basic types of lathe chucks.
Four-Jaw Independent Chuck
The four-jaw independent chuck is the most affordable type of lathe chuck. In this chuck each stepped jaw is independently operated by a different screw. Because of this, four-jaw independent chucks can clamp square, rectangular, round and irregular shaped materials using between two and all four of the available jaws. However, because of this versatility, using this chuck can be a slow and grinding process that requires lots of practice and the aid of an indicator gauge. The jaws of this chuck are also reversible for clamping inside or outside, which is useful with mixed combinations.
Three- or Six-Jaw Scroll Chuck
Three- or six-jaw scroll chucks are operated with a key that adjusts all the jaws at once. Scroll chucks are highly precise, fast and efficient and can work with changes of thousandths of an inch. However, they are not as accurate as a four-jaw chuck and the jaws are not reversible, so you need two sets for clamping inside or outside.
Four-Jaw Combination Chuck
Four-jaw combination chucks combine aspects of four-jaw independent chucks and scroll chucks. In a four-jaw combination chuck each jaw can be adjusted independently but all the jaws are opened and closed at the same time using a key. These chucks work well for repetitive work on square, rectangular or irregular pieces that don't require regular adjustments.
Jacobs Drill Chucks
Jacobs drill chucks are another common chuck type that work similarly to three-jaw scroll chucks, but they are designed with a long, accurate grips for use on drill bits and round stock. Jacobs drill chucks are generally used for drilling tailstock on lathes, but there are special models than can fit threaded lathe spindles that hold small, round bars in place.