[exmadscientist]

It doesn't shut itself off. It just stops cutting. It's like using concrete as a kitchen cutting board: that knife isn't going to do any damage, regardless of whether or not you stop pushing.

If you want to laser through metals, you need a different type of laser. Just as getting through concrete needs a different tool (say, a hammer chisel).

[linkdink]

The line sounded funnier to me in the less pedantic way.

[bombela]

Not a really good comparison I think.

A knife blade and a masonry chisel are roughly the same type of carbon steel tempered to a similar hardness.

They will both scratch and damage concrete.

[exmadscientist]

I'll grant that it's an imperfect analogy!

But would you like to chop through my sidewalk to get to the water main with a santoku?