Chucks that consist of cup-shaped holders having screws for holding the work are named poppet-chucks, or cup-chucks. Two or three such chucks of different sizes are made to fit one lathe, and are useful for drilling, boring, and screwing rings, nuts, lever-bosses, wheel-bosses, bushes, and other work that requires internal screwing and turning. A chuck of this kind is shown by Fig. 461, which has four fixing screws, and another cup-chuck with six screws is denoted by Fig. 462, this one being necessary for work that is too long to be held in a short chuck with four screws.

For several sorts of work that require boring, it is necessary to use chucks that are fixed to the carriage, instead of to the disc chuck. Poppet-chucks or boring-chucks to be thus fastened are shown by Figs. 463 and 464, both chucks being required to hold one tube or other piece of work which is to be bored. While in use, both chucks are at a proper distance from each other, and bolted to the carriage, the work to be bored being fixed in the chucks by means of the six screw-bolts. Each chuck consists of two half-round portions that are connected together with a joint and the bolt shown by B ; and when a piece of work has been bored and is to be taken from the lathe, the bolts shown by B and B are taken out, and the upper halves of the chucks are raised to allow the work to be lifted out.