82. Chain Swivel.—[Fig. 62]. Bending, scarfing, welding, and riveting. Material: about 2 feet of 7⁄16-inch round iron. Norway iron is the best, and this length is the most convenient for the first operations.
Fig. 62.—Chain Swivel.
Fig. 63.—Tool for Welding a Swivel.
For making this swivel, a special mandrel ([Fig. 63]) should be provided, made of 3⁄4-inch round, mild or tool steel, with a short offset of 3⁄4 inch; the gudgeon or pin which is shown at a should be 11⁄4 inches long, 7⁄16 inch in diameter at the shoulder, and tapering to 5⁄16 inch at the end. Any convenient length of handle that will prevent burning the hand when welding, will do.
Bend about 21⁄2 inches of the 7⁄16-inch round stock to a right angle, as at a, [Fig. 64]; make the corner as square as possible, by upsetting it before bending; or after bending, by using upright and backing-up blows. Flatten the bent portion b parallel with the bar, by first delivering the blows with the ball of the hammer to increase the width as much as possible, then finish it to 3⁄16 inch thick with the face of the hammer. The corner should be scarfed with the ball of the hammer and the rib worked out, as shown at c.
Fig. 64.—Steps in Making a Swivel.
Cut off the flat portion 2 inches from the bar, and form a thin scarf at the end of b. Notice that this should be formed on the same side with c. Beginning with the scarf at the end, the flat portion should be bent or rolled up so that the scarfs will overlap considerably, as indicated in the end view d. The special mandrel should now be inserted in the opening shown here, and all placed in a 3⁄4-inch bottom swage, while the scarfs are hammered into close contact.