(Caution. To avoid injuring the fiber of the metal and to upset it rapidly with the least amount of labor, always have the metal perfectly straight, and heat it only where the upsetting is required.)
Bring 4 inches of the central portion of the material to a white heat; if the heat extends beyond that distance, cool 21⁄2 inches of each end, then the upsetting will be confined to the desired place. Cool the ends quickly and thoroughly, so that the upsetting blows may be delivered before the heat has vanished. The material should be held vertically with the lower end resting on the anvil, while heavy blows are delivered on the top end, thus upsetting the heated metal.
Fig. 51.—Steps in Making a Pipe Hook.
These operations should be repeated until the center is 7⁄8 inch thick one way, with all excess metal forged on one side, as at a, and the three others perfectly straight. Now form a shoulder b, with overhanging blows, about 1⁄8 of an inch from the center or thickest portion, but draw it no smaller than 5⁄16 of an inch at the bottom. Then draw the metal marked c to an approximate dimension of 1⁄2 × 5⁄16 inch. Form this shoulder perfectly square, by holding it over a square corner of the anvil and delivering backing-up blows on the heavy end, while the drawn part rests flat on the anvil; the metal should be hot at the shoulder and cold on the end where the blows are to be delivered. Then use the flatter on the drawn end to smooth and draw it to the finished dimensions of 1⁄2 × 1⁄4 inch, making it perfectly smooth and straight on all sides. Cut off this drawn end 6 inches from the shoulder, as shown at d.
Draw the heavy end to a sharp, square point, making it straight on the side opposite to the shoulder and tapering from a point about 21⁄4 inches from the shoulder; this should also be made smooth with the flatter. Sketch e shows this so far completed.
Beginning 1⁄2 inch from the shoulder, bend the 6-inch end backward through its smallest dimension, to a semicircle of 3 inches inside diameter. An outline of the required semicircle should be inscribed on a plate, or models may be made to verify it. Sketch F shows the completed hook.
72. Gate Hook.—[Fig. 52]. Drawing, bending, and twisting. Material required: 71⁄4 inches of 3⁄8-inch square mild steel.
Mark lightly with the hardy on two edges 11⁄2 inches from one end, as shown at a. Form shoulders at these marks on three sides of the metal; do not make them too deep, as surplus metal will be required for bending here. Draw the metal at the shoulders just made, continuing to the end to 5⁄16 inch round and 21⁄2 inches long. Sketch b shows the work completed to this point.
Mark the opposite end on the same edges and in a like manner 41⁄2 inches from where the first shoulders have been formed; form shoulders at these marks and also draw down to 5⁄16 inch round, making the extreme end a smooth, round point, 21⁄2 inches long from the shoulders, as at c. Both of these ends should be round and smoothly drawn with the hand hammer.