When the nut and screw in the handy man's hand vise are worn out he can repair them as follows without using a screw-cutting lathe: First file the old spindle smooth. Then take two pieces of soft square iron, a and b, the size of the thread, and pin them to the spindle, as shown in Fig. 80. Now wind these iron bars around the spindle as tightly as possible. Under the bar b; place a small wire c, and wind it between the spindle and the bar, thereby raising bar b above bar a. As the bar b is to form the thread in the nut, it allows for some fitting, for it is to be attached to the inside of the hollow cylinder. When the required length is wound around the spindle, the ends should be pinned to the spindle, thereby holding the bars securely. (See Fig. 81.)

Wrapping the spindle with soft iron

Fig. 80 - Wrapping the spindle with soft iron.

The two threads coiled on the spindle

Fig. 81 - The two threads coiled on the spindle.

The finished spindle

Fig. 82 - The finished spindle.

The inside of the cylinder should be painted with black lead. Now, when the screw is forced into the hollow cylinder, the black lead will adhere to the outside of same, and will show just where they touch each other. Now take the screw out and file off all these marks, and repeat the operation until a good bearing is obtained all around the screw, that is to say, until the screw touches all around the cylinder. The threads and the hollow cylinder should both be marked so that the threads can be replaced in exactly the same position each time.

Section showing thread in nut

Fig. 83 - Section showing thread in nut.

Now remove the two pins in bar b and insert the screw as before, but drive it in tightly with a hammer. Then unscrew the spindle with the thread pinned to same (see Fig. 82) and it will be found that bar b has stuck to the inside of the hollow cylinder, as in Fig. 83. With a hack saw cut off the projecting ends. A couple of small pins may be driven through the cylinder and thread, thereby keeping the thread from shifting. Also a pin here and there may be put in the thread in the spindle. The screw and the nut must now be brazed with copper, as it is stronger than ordinary spelter.