How to make a square hole

How to make a square hole in any workpiece? Anyone can drill a round hole, but sometimes you need to make a square hole.

I needed to make a large square hole in a round blank so that the bar square, firstly, could move freely in the hole, and, secondly, so that there would be no large backlash. That is, you need a hole for a square of ideal shape and size. So the question arose - is it possible to do this with your own hands, not in a factory?

I have already had to do this, and therefore I answer - it can be done, but in the absence of a certain set of tools, it will not be possible to make a high-quality hole.

Will need

So, what is needed to make a perfect square hole:
Milling machine with cutting and slotting disc cutters, electric arc welding machine, lathe.

Making a square hole in metal

In order to make a square hole, we perform the following steps:
We clamp the workpiece in the milling machine and use a disk cutter to grind out a rectangular groove;

It turned out that the work goes much faster with a cutting cutter, and so I had to use it instead of a groove cutter. We perform a reverse replacement and, using a groove cutter, clean the corners of the workpiece.

We insert a square piece into the resulting groove, and another rectangular piece of metal into the remaining open upper part.


We weld this small piece to the main blank with an electrode using conventional arc welding.


We clean the resulting element from adhering metal, which is best done using a lathe, completely turning it out and grinding it.

As a result, we get a round blank with 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 improvised tools, using only an angle grinder, which is popularly called an “grinder”, a vice and a welding machine.
But in this case, firstly, you will have to sweat a lot, and, secondly, the product will not turn out so smooth.
When performing this work, it is imperative to comply with safety requirements:

• when working with milling and lathes, mechanic's glasses are required;
  
• When performing welding work, gloves and a welding mask are required.

This is how, if you wish, you can make a square hole of any size no worse than the factory one!

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