Scientists discover that human hair can ‘chip’ metal blades despite being 50 times softer than steel

Your razors get dull, but do you do what causes it? It’s actually your hair that ‘chips’ away at the metal blades, and dulls them. Now, this is quite the discovery considering that your hair is 50 times softer than steel.

Engineers at the Massachusetts Institute of Technology (MIT) studied closely the ultra-fine detail in shaving experiments with an electron microscope to see how a razor blade can be damaged as it cuts human hair.

Despite hair’s relative softness in comparison to the strength of steel, the edge of the blade dulls quickly after a few short shaves. 

Defects in the steel’s microscopic structure combined with the angle of a shave can chip the blade even with a single stroke, researchers reveal. 

Once this initial crack forms, the blade is vulnerable to further chipping, and as more cracks accumulate around the initial chip, the razor’s edge can quickly dull. 

“Our main goal was to understand a problem that more or less everyone is aware of – why blades become useless when they interact with much softer material,” said study author C. Cem Tasan.

The study suggests ways for current blade technology to be improved, thereby lengthening the lifetimes of commercial disposable razors and kitchen knives.