When a piece of metal is to be drawn to a smaller dimension, with shoulders opposite each other, on either two or four sides, these blows will produce the required result to the best advantage. They are more effective if the metal is held at a slight angle across the edge of the anvil face, but then the hammer blows must be delivered a little beyond the anvil edge, so that the upper and lower depressions in the metal will be formed exactly opposite each other, as shown at b, where the depressions are indicated by the broken lines.
In forming shoulders such as are required on the hasp exercise (page [64]) the first pair may be formed as shown at b and the second pair as shown at c. In the latter case the metal is held across the nearer edge of the anvil face and the blows delivered in a manner similar to that described in the preceding paragraph. Hammer blows of this class may be used on any edge of the anvil as required.
47. The overhanging blow is delivered so that half the width of the hammer face extends over the edge of the anvil. (See [Fig. 24].)
Fig. 24.—The Overhanging Blow.
It is used for forming shoulders on one side of the metal and for drawling out points of scarfs. When blows are delivered in this manner, the anvil will form a depression or shoulder on the lower side of the metal, and the hammer will keep the metal straight on the upper side.
This blow also will be more effective if the metal is held at a slight angle across the edge of the anvil face, but the blows must always be delivered squarely on the upper side of the metal to keep it straight.
48. The beveling or angle blows are delivered at any angle that the form of the work may require. When the metal is to be drawn with a taper on one side, it must be held level on the anvil and the blows delivered at an angle determined by the amount of taper required. Figure [25] shows the manner of holding the metal and the way the blows are to be delivered.
