- Joined
- Oct 29, 2012
- Messages
- 1,329
Chips are hot, we all know that, but (scientifically speaking), why are they so hot? The question is like "why is the sky blue?" and the answer is probably equally above my head but I'd still like to hear it if anyone knows the answer.
I know there is some friction involved but I don't think that's the whole story. There is shearing action too which generates heat (friction again?) But that doesn't feel like an adequate explanation either. I've never had a paper burst into flames from being cut with scissors. Have you ever cut metal with large shear press? Did it get skin-melting hot?
It seems to me that chips are hotter than they should be, at least as far as can be explained by the physics that I currently understand.
I'm pondering this as I look at the gnarly brand in the palm of my hand filling up with burn juice. Earlier today I was using a step drill to drill a hole into an electrical panel from the bottom up, when a wicked chip fell down and ended up between my hand and the drill grip. This is an exceptionally sharp step drill, very fast; it makes chips 1/16"-1/8" thick, that make a solid "ting ting" sound when they hit ground, sounds like framing nails falling on the ground. The chips are hard to bend by hand. Chips from lesser step drills are not this hot. Chips from normal twist drills are not this hot. This contradicts my expectation, which is that a sharper, more efficient drill does much more cutting than rubbing, and therefore the chip should be cooler. Something is going on here that I don't understand.
I know there is some friction involved but I don't think that's the whole story. There is shearing action too which generates heat (friction again?) But that doesn't feel like an adequate explanation either. I've never had a paper burst into flames from being cut with scissors. Have you ever cut metal with large shear press? Did it get skin-melting hot?
It seems to me that chips are hotter than they should be, at least as far as can be explained by the physics that I currently understand.
I'm pondering this as I look at the gnarly brand in the palm of my hand filling up with burn juice. Earlier today I was using a step drill to drill a hole into an electrical panel from the bottom up, when a wicked chip fell down and ended up between my hand and the drill grip. This is an exceptionally sharp step drill, very fast; it makes chips 1/16"-1/8" thick, that make a solid "ting ting" sound when they hit ground, sounds like framing nails falling on the ground. The chips are hard to bend by hand. Chips from lesser step drills are not this hot. Chips from normal twist drills are not this hot. This contradicts my expectation, which is that a sharper, more efficient drill does much more cutting than rubbing, and therefore the chip should be cooler. Something is going on here that I don't understand.