Scissors are hand operated tools use to cut materials into desired shapes and sizes. At their core they put into practice one of the simplest concepts of physics (the lever) by having two edged blades that meet each other when the handles are pressed together, thus catching the material in between the two blades and cutting it. Larger variants are called Shears but operate under the same premise.

Scissors were invented in Egypt approximately 3500 years ago but the mechanism and usage remain the same; as a simple but effective method for individuals to divide materials such as paper and string which intrinsically don’t come in particular sizes.
Scissors are easily recognisable by their very design:

• The blades are where the material is placed, as when the blades meet they cause a shearing motion which cause the scissors to slice through. They are sometimes given a sharp edge but, due to the shearing effort the pivot provides, this isn’t always required. Standard scissors are generally between 2 and 5 inches in length and are usually made of metal, although sometimes they are made from plastic when safety is required over cutting ability (such as childrens scissors)

• The handles are where the user operates the tool; by putting their thumb and finger into each of the handle holes and bringing the handles together and apart in sequence, the blades perform the same action and generate the shearing motion. The holes in the handles are made to incorporate the thumb in one and one or two finger in the others so they are seldom less than an inch in diameter; often the second handle hole will be an oblong shape to fit two fingers at once. Usually comprising the last 2 inches of the final tool, sometimes the blade is designed as a single piece of metal that has the handle holes at the end, but most of the time the handles are separate pieces of plastic that are applied to the blade ends afterwards

• The pivot is the essential part of the scissors which gives the handles control over the blades. Because of the nature of a lever, as a result of the pivot a greater force is applied to the blades than if the user had pulled the blades themselves, thus allowing them to cut materials will relatively less effort. The closer the material is to the pivot, the greater the force provided. The bolt pin used for the pivot is almost always metal, unless the scissors are produced with low costs in mind or for non-strenuous use in which case it may be plastic.

With exception to specialised scissors that have specific requirements, most scissors encountered will be between 3 to 8 inches (7.5 to 18cm) in length, have metal blades with plastic handles and weigh no more than 4 ounces (100g)

An interesting thing to note is that, despite the symmetrical appearance, scissors are left and right handed as a result of the blades having to overlap. The scissors pictured above are right-handed because the blade on the right is the one on top, and the reverse is true for left-handed scissors.

Scissors are very easy to use; by moving the handles back and forth the blades do so in kind and give it the ability to cut with more force than is inputted thanks to the pivot. This allows the user not only to create small cuts, breakages or incisions in materials but also to shear large portions. Many scissors varieties exist to perform and excel in a particular aspect of cutting, for example:

• Tailors scissors have sharpened blades and a spring to add tension when cutting so as to minimise any splitting or fraying of expensive materials such as silk
• Nail scissors have the blades curving up and away from the body of the scissors so that the tips of the blades don’t catch the users fingers or toes
• Cigar cutters have crescent shaped blades that match the shape of the cigar when they are brought together so as to avoid deforming or damaging the cigar

The concept for scissors has evolved since they were first made. Electronic devices such as hedge trimmers or hair clippers work under the same rules that allow scissors to work; but scissors themselves will always have their own place in the world. The simplicity of their design and the universal need to edit and shape materials mean that scissors, in whatever shape or form, will be somewhere near you.