Locksmiths, mechanics, car enthusiasts and ordinary people who know how to use tools, during their work often encounter situations when they may need to make a square hole in one or another metal (steel) part or product. Purchasing special equipment or ordering similar work from a factory is quite expensive. There is a budget alternative - making a special punch from materials available to everyone.
Tools and materials used
To obtain high-quality square holes you will need the following products and tools:- reinforcing rod or its replacement (made of a good grade of steel) 20-30 cm long of the required diameter (selected so that a square of the required dimensions can be “fitted” into its circle);
- vice;
- marker;
- ruler;
- calipers;
- round file
- hand grinder (“grinder”) with a metal wheel;
- metal container with water;
- propane torch;
- drill or drilling machine;
- hammer.
Making a punch
On the reinforcing rod, one of the sides (round) is marked in the form of an “inscribed” square of the required dimensions. Next, the reinforcement is clamped in a vice parallel to its “jaws” and, using a grinder, is ground on 4 sides to the required size. To obtain maximum accuracy, a caliper is used, which makes it possible to check the current size of the part.
Having made a square-type workpiece on a piece of reinforcing bar, it will be necessary to “sharpen” it in a special way, using a very small grinder circle and a round file. It will be necessary to vertically fix the part in a vice, and gradually create a semicircle between the adjacent vertices of the square. A round depression should form in the center of the end part of the product.
After the tops of the square (the end part of the part) have become sharp “spires”, it will be necessary to fix the part horizontally in a vice, and harden the part using a regular propane torch, with which the square part of the product is heated until reddened, and then cooled with water.
After such processing, the square part of the part (punch) becomes stronger and more rigid.
Making square holes
In the right place, the workpiece in which a square hole will need to be made is drilled using a drill or drilling machine with a drill of the diameter that “fits” into the desired square of a certain size. After this, the workpiece is placed or secured on a reliable, strong surface (for example, a vice, a wide sheet of metal, etc.), and using the resulting square punch and hammer, the desired hole is made. The workpiece itself must be placed so that the part where the square hole will be is not adjacent to the very surface of the base.
The hammer strikes are carried out in the center of the reinforcing bar and with medium force. Thus, a square is “knocked out” from a round hole, and the “excess” metal is simply squeezed out by blows of the punch.
It is important to know that you can make a punch not only “sharpened” on all four edges. and with one. In this case, it will look like an ordinary chisel, and when knocking out a square in the workpiece, it will need to be rotated 90 degrees with each blow of the hammer. In addition, as such a punch is used, it becomes dull and will need to be sharpened from time to time.
