Material. Mild steel, 16 mm in diameter, 200 mm long.
Additional tools. Round, tapered punch about 12 mm in diameter with flattened end (Fig. 77); bending fork and bending dog (Fig. 77); 30-mm bottom swage; 16-mm bottom swage.
To begin forging a solid hook for chain (Fig. 78D), heat one end of the 16-mm rod to near-welding heat and chamfer in a 16-mm bottom swage. Cool this end and take a near-welding heat on the opposite end. Cool to restrict heat to within about 30 mm of the end and begin upsetting in the 30-mm bottom swage. Straighten as necessary. Continue heating and upsetting in the swage until the upset fills the diameter of the swage and is about 3 mm thicker than the original diameter (Fig. 78A). As upsetting proceeds, some flattening of the sides in the one direction is called for (Fig. 79).
When the end is of correct size and neatly formed, mark the centre of the hole which now has to be punched. It should be on centre across the work but about 2 or 3 mm more from the end. (For example, if the centre of 30 mm equals 15 mm, the distance from the end should be 17 to 18 mm.)
The upset end is again heated to a yellow heat and placed on the anvil face with the mark upwards. The punch is positioned on the mark and struck firmly with the hand hammer. After two or three blows, quickly cool the punch before proceeding. In all punching operations the punches must not be allowed to become too hot and so must be cooled. Hot punches distort in the hole, giving wrong shapes, and they can become firmly fixed in the work. When the punch is removed for cooling, a little coal or coke dust can be sprinkled into the hole. When the punching continues, this dust will generate gases that assist in the removal of the punch. As soon as a dark patch can be seen on the opposite side of the work, indicating that the punch is nearly through, the job is turned over and punching is continued from the now-top side. A small piece of metal will be removed (Figs 80, 81 and 82).
The punch can now be driven through from alternate sides until a neat hole of 12 mm in diameter is formed. This can be done by allowing the punch to protrude through the punching (pritchel) hole. Should this hole be too small, a bolster plate must be used. (The anvil tool hole is too large.) The eye is next finished over the beak (Fig. 83). Hammer blows are vertical and on the centre of the beak. Work is held at the angle shown and rotated around the beak as hammering proceeds. This gives a chamfer to the inside of the hole, providing better protection from the rubbing of any attachments, such as chain links. Finally, the eye is slightly bent to one side (Fig. 78B). Fix a pair of tongs that are a good fit on to the eye. Take a near-welding heat on the end opposite to the eye for a length of about 60 mm. Forge a point (Fig. 78C). Start with an abrupt point on the end and elongate as necessary. The final length of the point should be approximately one-third of the length measuring from beneath the eye. This point should incline in the direction opposite to the bend in the eye.
The point must be forged to a square section first, corners removed and finally rounded up. Place a bending fork in the tool hole of the anvil and have the bending dog at hand. Heat the centre section of the job to a bright red heat, making sure that the temperature is even along its length. Place in the bending fork and with the aid of the bending dog bend to hook shape. The end of the point should reach to the underside of the eye. See Figs 84 and Fig 78D. At this stage the point should not be closer than 30 mm to the eye.
The centre of the hook is again heated to a bright red or yellow heat, placed on the anvil (Fig. 85) and the outer part of the metal thinned to give the section shown in the Fig. 85 inset. The job is now brought to a red heat all over and adjustments made. It should lie flat on the anvil face with no distortion. The end of the point should be about 12 mm from the eye to allow for the insertion of chain. Some designs have the point turned out a little. Simpler hooks can, of course, be made with unwelded eyes, but they are weaker. Solid forged hooks of all sizes can be made in the way shown here.