constantino675 t1_j2dusma wrote on December 31, 2022 at 3:05 PM

Reply to comment by DrySyllabub2563 in ELI5: What makes the rust on a rusty nail different from the rust on shaving razors to where one needs an immediate tetanus shot and the other happens daily by DrySyllabub2563

You're half right. The biggest contributor to dulling is mineral deposits from drying cycles.

If you dry the blade after every use (including a blast of compressed air) the blades can last 150+ shaves with minimal wear.

Antman013 t1_j2dx9kv wrote on December 31, 2022 at 3:24 PM

This is EXTREMELY difficult to accomplish, however, and usually only done by folks wanting "bragging rights". So called "century shavers" . . . in a practical sense, there is simply no need to be this fanatical about edge wear on disposable blades.

I have seen what both a safety blade and a straight razor edge look like under an electron scope, and u/Berek2501 is correct. The "edge" is actually a line of "peaks and valleys" which, after contact with your hair, have the tips rounded off or over. Honing is done to "straighten" or realign those peaks and valleys and restore that keen edge. It's quite fascinating to see how "uneven" a truly "straight edge" is under extreme magnification.