Rings and eyes forged solid without any welds may be made in the general manner described below. As an example, suppose;t be required to make a ring such as illustrated in Fig. 101. It is necessary, of course, to calculate the amount of stock required. This may be done as follows: The first step is to determine the area of the ring, which is done by taking the area of the outside circle, and subtracting from it the area of the inside circle, as follows:
Outside circle area
12.57 sq. in.
Inside circle area
7.07 sq. in.
5.50 sq. in.
The stock used when making small thin rings should be twice the width of the side of the ring to which is added at least 1/4 inch. A flat bar is first forged rounding on the ends, punched and split as shown; this split is opened out and the ring is hammered into shape. When the bar is split the stock is more or less deformed and when worked back into shape is slightly thinned. Although no stock is lost by the hammering, an allowance must be made for the thinning and stretching and it is necessary to make the stock slightly wider on this account, as noted above. Allowing 1/2 inch for hammering, and taking stock 1 1/2 inches wide, the amount of stock required would be 5.5-5-1.5, equal to 3.66 inches. Allowing a small amount for loss by scale, etc., 3 11/16 inches of stock should be taken. In making this calculation, the thickness of the stock is not taken into consideration, as the thick-ness of the finished ring is the same as the stock. This general method is used on a large variety of work, particularly where rings are to be made of tool steel and should be made without a weld. Another method of making weldless rings, under the steam hammer, is illustrated in Fig. 102. The proper amount of stock is first forged into a disc, a hole is punched into this disc and a mandrel inserted. A U-shaped rest is then placed on the anvil of the steam hammer and the mandrel laid on this. The ring is turned on the mandrel and forged into shape. Larger and larger mandrels are substituted as the hole in the ring increases in size.
Fig. 101. Weldless.
Fig. 102. Weldleas Ring Made under Steam Hammer.