Combination-chuck. A chuck in which the jaws may be moved simultaneously or independently.
Comparator. A machine for comparing measurements, for testing them and originating sub-divisions.
Compass-calipers. A pair of calipers having one bent leg and one leg with compass joint.
Compasses. A tool answering the same purpose as dividers, but with longer legs and a set screw to secure the position of the legs.
Compass-plane. A plane whose sole or bottom is curved in its length.
Compound gears. A train of gear wheels in which there are two wheels fixed on the same shaft but of different diameters so as to vary the velocity.
Compound slide-rest. A slide-rest having two slides, one above the other.
Cone-bearing. A bearing (for a journal) that contains a coned sleeve that may be moved endways to take up wear.
Cone-mandrel. A mandrel that holds hollow work by means of two cones.
Cone-plate. A device for steadying work in the lathe by supporting one end in a coned mouth.