Chromium Steel
The effect of this substance is analogous in some features to that of manganese; in others to that of carbon upon steel, imparting a fine close texture and increasing hardness and brittleness. Chucks are pieces of wood, slightly wedged, to be driven fast between the bars of a flask to impart stiffness to the bars; or, for driving down below the straight bars to form a continuation of the latter, as it were, into parts which extend below the joint, and which must be lifted out along with the flask. By this means a plain flask may be made to correspond to any and every form of joint conceivable, and the task of carrying a deep lift is much simplified. This useful device is often called chocking.