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Different types of scissors - sewing, kitchen, paperScissors 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.
Unlike a knife, scissors have two pivoted (or hinged ) blades. Most types of scissors are not particularly sharp; it is primarily the shearing between the two blades which cuts. Children's scissors are even less sharp, and are often protected with plastic.
Although often used interchangeably with "scissors", the term shears are reserved by those in the industry for scissors longer than 15 cm1.
Although commonly ascribed to Leonardo da Vinci, scissors were likely invented in 1500 BC in ancient Egypt2. These were likely shears with the joint at the far end3. Modern cross-bladed scissors were invented by Romans around AD 100.
Mechanically, scissors are a first-class, double-lever with the pivot/hinge acting as the fulcrum. For cutting thick or heavy material, the mechanical advantage of a lever can be exploited by placing the material to be cut as close to the fulcrum as possible. For example, if the applied force (i.e. the hand) is twice as far away from the fulcrum as the cutting location (e.g. piece of paper), the force at the cutting location is twice that of the applied force at the handles. Specialized scissors, like bolt cutters exploit leverage by having a long handle but placing the material to be cut close to the fulcrum.
Left handed scissors
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.
Specialized scissors
- Pinking shears are scissors with a serrated cutting edge.
- Tin snips are scissors for cutting through sheet metal, for example tin plate.
- Pruning shears and secateurs are scissors for cutting through branches of tree and shrubs.
- Bolt cutters cut through heavy wire and bolts
- A hemostat resembles a pair of scissors but has a locking clamp instead of a blade; it is used in surgery
- Nippers cut small pieces out of tile
Other meanings
Scissors is also a party game as is Rock, Paper, Scissors.
Scissoring is also a lesbian sex term. It's when two women spread out their legs in opposite directions and interlock with each other while rubbing back and forth.
Scissor Sisters is a pop band.nl:Schaar