How to make a square hole

How to make a square hole in any workpiece? Everyone can drill a round hole, but sometimes it becomes necessary to make a square hole.
I needed to make a large square hole in the round billet so that the bar square, firstly, could move freely in the hole, and, secondly, that there was no big play. That is, you need a hole for a square of perfect shape and size. So the question arose - is it possible to do this with your own hands not in the factory?
I already had to do this, and therefore I answer - it can be done, but in the absence of a certain set of tools, a quality hole cannot be made.

Will need

So, what you need in order to make a perfect square hole:
Milling machine with cutting and grooving disc milling machines, electric arc welding machine, lathe.

Making a square hole in the metal

In order to make a square hole, we perform the following steps:
We clamp the workpiece in the milling machine and with the help of a disk mill we grind a rectangular groove;
It turned out that the work is much faster with the cutter, and therefore had to put it instead of the groove. We make a reverse replacement, and with the help of a grooving cutter we clean the corners of the workpiece.
We insert a square billet into the resulting groove, and another rectangular piece of metal in the upper part that remains open.
This small piece is welded to the main blank with an electrode using conventional arc welding.
We clean the resulting element from adhering metal, which is best done with a lathe, having fully machined and polished.
As a result, we get a round billet in which there will be a perfectly square hole.

How to make a square hole with improvised tools

All these technological cycles can be done with the help of simple tools at hand, using only an angle grinder, which is popularly called the “grinder”, a vice and a welding machine.
But in this case, firstly, you have to sweat a lot, and secondly, the product will not work out so even.
When performing these works, it is imperative to comply with safety requirements:

• when working with milling and turning machines, locksmith glasses are required;
• when performing welding work, mittens and a welding mask are required.

So, if you wish, you can make a square hole of any size no worse than the factory!