The 4 Jaw self-centering chuck is very easy to use. It can hold round and square shaped materials. Unlike the Independent 4 Jaw chuck, the jaws on the 4-jaw self-centering chuck all move at the same time allowing the user to load and unload parts very quickly.
The 4 Jaw self-centering chuck will not be as accurate as the Independent Jaw chuck (part #1030) since you are relying on all 4 jaws to move in exact synchronization. But for some applications (usually wood) the self-centering chuck works fine. If ultra-precision is needed the Independent 4-Jaw chuck (part# 1030) should be used.
Note: DOES NOT FIT THE NEWER ER16 HEADSTOCK.