# Why does Guillotine have of 45 degreed blade rather than the one parallel to the ground? [closed]

What is the point of having 45 degreed blade in Guillotine? After all, the pressure-Force over Area-blade imposes to the neck is the same either way.

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## closed as off topic by Marek, space_cadet, Cedric H.Dec 27 '10 at 12:11

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Frankly, I'm curious about the answer, although not so much I'd be interested to do much work looking for it myself. – Raskolnikov Dec 27 '10 at 9:20
@Comptrol: Try cutting potato when you hold knife horizontal its bit difficult but when you hold it slanted it is somewhat easier. What I am thinking is it would require heavier blade if the blade is parallel to the ground. I guess smaller part of blade touches the neck providing more pressure. If you rephrase it I will vote to reopen it. (also google reason for slanted blade of guillotine) – Pratik Deoghare Dec 27 '10 at 19:11
Why closed? I think there is a physics related answer to this. It has to do with the contact mechanics, and the strength of materials. – ja72 Dec 30 '10 at 18:34
To the folk, I found the answer thanks to @ssg. With 45 degree, blade can move downwards fast. and along with the sharpness and weight of the blade, this movement results in separation of the head from the body. And why the 45 degree but not another one? I think, if the angle was larger, that might not contribute enough weight and pressure. and if it was smaller, the blade might not move downwards just as fast and cutting wouldn't occur. – Özgür Jun 30 '11 at 4:02
Just stumbled on this. It's actually a good question, too bad they shut it down. I don't think the answer has to do with the pressure force distribution or anything, but rather with the transverse motion of the blade at the contact point. My guess is the transverse motion inhibits microscopic binding between the blade and matter being cut. – user1631 Oct 28 '11 at 17:19