The Science Behind: Scissors

Scissors are a wonderful tool that helps us in our daily lives that many of us take for granted. For most people they believe that scissors are just two pieces of sharp metal held together by an axis, but that is only part-way true. Scissors are a very unique object that helps cut paper and other material, but what makes them so special? Well, let me tell you.

            Scissors are a combination of machines such as the lever, and the axel, I call this a complicated machine. A normal lever looks like this:

But as scissors are a little more complicated, they do not exactly look this way. Since they are two levers and an axel, they look more like this:

            The edges on a pair of scissors are not really that sharp, take them apart and it would be really hard to but paper without the axel, if possible at all. But that is where the physics comes into play here; you don’t think physics has anything to do with scissors? Why, let me prove you wrong! Close a set of scissors, and what do you see? A giant gap? I am positive you see one. At first you think the scissors will not cut anything due to that, but that gap is where the cutting action comes into play.

            A careful observer can see that both blades are tilted inward just the slightest amount, this helps a lot in cutting the item. As you close the scissors the gap gets wider, but it disappears as you open them. As you can tell just by observation is that the two blades of the scissors are always touching each other.  That is because the two blades are rubbing against each other, this causes enough force along with the sharpness of the blade to cut the paper, plastic, etc. Over time this tilt can disappear and the cutting action disappears, as you can tell with older scissors it is usually easier to cut near the axis than near the tip. The cutting action is not usually because your scissors are dull unless they rust. Paper and plastic does not erode the sharpness of stainless steel, stainless steel is mostly iron and carbon and a microscopic coating of chromium. Many companies will have you think otherwise and you buy that new scissors sharpener, this may help a little bit but in the long run it is easier to just buy a new pair of scissors.

hope you had fun learning!

Other articles written by me:

http://scienceray.com/chemistry/the-science-behind-neon-lights/

http://scienceray.com/chemistry/paints-and-pigments-and-their-elements/

http://scienceray.com/biology/ecology/water-vs-soda-the-fact-and-the-fiction/