Scissors

Scissors are a tool used for cutting thin material which requires little force. They're used for cutting, for example, paper, cardboard, metal foil, thin plastic, food, cloth, rope and wire. They are also used for cutting hair and nails.

Left handed scissors

Consider the case of a paper cutter. It clearly is left-handed or right-handed. Scissors are mechanically equivalent to paper cutters and likewise can be left or right-handed.

Related Topics:
Paper cutter - Left-handed - Right-handed

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Because scissors have overlapping blades, scissors are not symmetric. This asymmetry is true regardless of the orientation and the shape of the handles: the blade that is on top always forms the same diagonal regardless of orientation. Human hands are also asymmetric and worse, when closing the thumb and fingers do not close vertically, but have a lateral component to the motion. Specifically, the thumb pushes out and fingers pull inwards. For right-handed scissors, the thumb blade is closer to the body so that the natural tendency of the hand is to force the cutting blades together. Furthermore, with right-handed scissors held by the right-hand, the shearing edge is visible. Conversely, if a right-handed scissor is held in the left hand, the natural tendency of the left hand would be to force the cutting blades laterally apart. Worse, the cutting edge of the scissors would be behind the top blade, and one cannot see what is being cut.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Ambidextrous scissors are not truly ambidextrous. They have symmetric handles so their is no distinction between the thumb and finger handles. They have very strong pivots so that the blades simply rotate and do not have any lateral give. However, even if the (right-handed) scissor successfully cuts, the blade orientation will block the view of the cutting line for a left-handed person.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Using scissors designed for the wrong hand is very difficult for most people. They have to unnaturally force the blades together to cut and stretch their necks over the top blade to see what is being cut.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~