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The more a beginner has in his arsenal, albeit theoretical knowledge, the easier it will be for him in practice, there will not be a long way through trial and error.
Let's talk today about one thing that can arise when cutting metal with a grinder. To be honest, a comment on one of the channel's articles prompted me to think about it.
A person writes something like it is good to cut with a grinder, when the metal is heated to red with a disc, but this is fundamentally wrong. Let's figure it out, let beginners know this and do not make such a mistake.
When cutting metal with a grinder, burning sparks will fly out from under the disc in any case. This is normal, this is the way it should be. The mechanism of the formation of these sparks is such an abrasive disc, which is harder than the metal itself at high speed, as it were, strips off a piece of metal from a solid mass.
This small piece from great friction at this moment instantly heats up to red, well, here, although it depends on what kind of metal, there may be a different color. The main thing is that this piece will glow and fly, and there are thousands of such pieces, maybe tens of thousands, I have not counted!
This creates a stream of sparks that we see very well. Sparks fly from under the circle, the metal is gradually cut.
But maybe the following picture will turn out when cutting. The metal next to the spinning disc begins to heat up red. It is the metal itself, not the sparks. And at this moment we feel that the grinder's disk seems to stop cutting, biting into the metal. Why is it so?
The metal heated to redness becomes ductile, so the blacksmiths make anything from such a heated piece, it is malleable like plasticine.
Now imagine that the abrasive of a circle cuts into a heated plastic mass of metal. It is no longer possible to tear off pieces of metal here. The abrasive will rub, as it were, but not tear off the metal. Imagine a piece of dough and we will try to grate it, nothing will come of it.
And a beginner, due to little experience, if he feels that the grinder has almost stopped cutting, and then the metal just heated up to red under and next to the disc. And it presses on the disk even more and this aggravates the situation, the heating becomes stronger and more extensive.
And it was only necessary to slightly shift the disc a little further along the markings, and after a couple of seconds go back and continue to cut normally further. Or, initially, the disc is not trying to bury it in the metal, but is kept on the surface in one place. The disc rotates, the resistance is large, since the length of the contact between the disc and the metal is large and long.
There are many options for heating the metal to red, but for now, a beginner just needs to remember. You feel that the disc is spinning, but does not cut, look at the color of the metal next to the disc, now you know why.