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Scientists have found why razor blades become
after use. They found out why blades lose their
. Razors are 50
harder than hair, but hair damages the
of a blade. Razor blades are made from
. They are toughened with carbon. Each
a blade cuts a hair, the hair damages the blade a
. A blade can cut
of hairs. This means the
of a razor blade is short. It needs to be replaced
.
