Thread: Iwasaki western style

Originally Posted by Bruno

Tamahagane is not necessarily harder. It all depends on the heat treatment. For a katana I thought the rule of thumb was 60-40. 60 HRC for the cutting edge and 40 for the spine.

67 would be virtually impossible to hone, and extremely brittle on a hollow ground razor. So has a knife or cutter that is HRC 67. IIRC he called it virtually defective. It was nearly impossible to hone and very brittle so the edge would crumble away when used incorrectly. I doubt a razors edge on 67 HRC would last long (if you could get it shaveready).

Maybe. Different steels will take different levels of hardness without getting brittle. I've got an O1 blade from Robt Williams that is 65HRC and shaves and hold an edge fine, and had a stainless blade that would chip against my whiskers at only 64HRC.

I'm not sure how relevant So's knife is. It may well be that a tamahagane knife would be too brittle at 67 HRC while a razor would not be. Many western-made razors are much harder than knives of the same vintage, and are extremely brittle and will utterly shatter if dropped on the floor, yet shave and hold and edge extremely well.

I was playing with my western-styled tamahagane razor the other day and it's very hard indeed. Not sure how hard exactly, but it seems to be harder than my 65HRC Robt Williams razor. A few years ago I took my Chronik to a local lab for Rockwell testing but I'm not terribly interested in getting my tamahagane razor onto a tester, since the rib on mine is too small to test on, it's very thin and vestigial like the TI Silverwing, so they'd have to test it on the blade itself and that's just asking for trouble. Maybe if I had two of them...