Scientists from MIT have discovered why razor blades become blunt after repeated use. They did research into why razor blades lose their sharpness. Razor blades are 50 times harder than the hairs they cut. Even though human hair is 50 times softer than the metal of a razor blade, the hair damages the edge of the blade. Razor blades are made from stainless steel. They are usually coated with tougher materials like hardened carbon. The MIT scientists said that each time a blade cuts a hair, the hair causes tiny amounts of damage. A blade usually cuts thousands of hairs in one shaving session. This means the life of a razor blade is limited and will need to be replaced regularly.

Adapted from https://breakingnewsenglish.com/

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