Scientists discover why shaving blunts razors

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".