Nail file

A nail file is a tool used to gently grind down and shape the edges of nails. They are often used in manicures and pedicures after the nail has been trimmed using appropriate nail clippers. Nail files may either be emery boards, ceramic, glass, crystal, plain metal files or metal files coated with corundum (sapphire).

Emery boards are pieces of cardboard which have emery or emery paper glued to them, making them both abrasive and flexible, used for fingernail and toenail care. They are used by manicurists to shape and smooth the nail during manicure and pedicure sessions. Emery boards are inexpensive and disposable, making them a sanitary alternative to metal nail files. The emery board was first patented by J. Parker Pray of New York in 1883.

Emery boards are generally less abrasive than the metal nail files, and hence, emery boards may take longer to file down nails than metal nail files. However, nail files may play a role in disease transmission if they are used on more than one person without adequate sterilization. Emery boards are usually less expensive than metal nail files, therefore emery boards can be economically disposed of after use on a single person. The nail can be smoothed and shaped accurately by taking light, even strokes in one direction across the top of the nail. Twenty to thirty easy strokes can typically shorten excessively long fingernails, while five to ten strokes are sufficient for shaping the nails.

Guitar players have also been known to use emery boards to smooth out calluses which may snag the strings of their guitars.

Baseball pitchers and cricket bowlers have been known to use emery boards to scuff the outside of the ball. The roughness can offer more grip and hand control. Surface scratches also alter the ball's aerodynamics making it more susceptible to spin and movement when in flight. However, the deliberate manipulation of the ball using an emery board is classified as cheating in baseball and cricket.

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