I had lost hope with my electric cooking plates. The white circles where completely hidden under a layer of diamond-grade burn residue that no amount of scrubbing with chemicals could even begin to remove. I found this 3€ scrapping tool and it’s amazing !!! Sorry, but I don’t have the before picture, believe me after 6 years of usage, it was bad.
I looked a bit more into it and the first spec I found had a knoop hardness of 600 which should be mohs 6-7 so hardened steel should be able to scratch it.
Is mnoop hardness a special hardness scale for gemstones or something? Never heard of that before. I’m not an actual mechanical engineer though, just a dropout lmao
I read that its used to measure the hardness of brittle materials, but I could be wrong.