Scientists found why razor blades lose their sharpness. Razor blades are 50 times harder than hair, but hair damages them. Razor blades are made from steel. Every time a blade cuts a hair, the hair damages the blade. Hair makes the blade blunt. This means the life of a razor blade is short. It needs to be replaced often.

The scientists got a close-up view through a microscope of a blade cutting a hair. The hair made a small hole on the blade. This hole got bigger as it cut more hair. After more shaving, the blade did not cut cleanly. A scientist said it was interesting that steel failed when it cut hair. He said this is "an important engineering problem".