Eye bolts are made by two general methods, being either solid or welded. The solid eye bolt is much stronger. A solid eye bolt, or forged eye, as it is sometimes called, may be started in the general manner illustrated in Fig. 65. A nick is made on either side of a flat bar by using top and bottom fullers as illustrated. The end is then rounded up as shown in Fig. 66. Particular attention should be given to seeing that the eye is forged as nearly to a perfect circle as possible before any punching is done. The stock around the eye is rounded up over the horn of the anvil as at A, by swinging it back and forth as it is hammered. The hole when first punched is like B, but when finished should be like C. The other end of the bar is then drawn down to form the round shank. If a very long shank is wanted a short stub shank may be formed in forging the eye and a round bar of the proper size welded on.
Welded eye bolts may be made in two different ways. The easier method produces an eye shaped as in Fig. 67. To make such a bolt, first scarf the end so that it will fit over the bend of the rod along the dotted line ab. Bend the eye over the horn of the anvil. Finally bring to a welding heat and weld in accordance with instructions already given.
Fig. 65. Starting Solid Eye Bolt.
Fig. 66. Rounding Up Solid Eye Bolt.
An eye of better appearance, as shown in Fig. 68, is made as follows: Upset the body of the metal as a seat for the scarf at the end, as shown at a. Scarf the end of the bar and bend over the horn of the anvil into a true circle to fit the seat at a, and then weld as before.
The length of metal required for an eye or ring is nearly equal to the length of the circumference of a circle whose diameter is equal to the mean diameter of the ring. Thus in Fig. 68 the length required for the eye will be approximately the length of the circle abcb whose diameter is ac.