19c27

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Nov 24, 2003
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Came across 19c27 for the first time this past Friday. I past by to pay for some laser cutting of my designs in 12c27 when I was properly introduced to the new steel in RSA.

Several knife makers had made the dealer examples in 4mm and I had a chance to test them (without destruction testing). The carving knife was 60RC and flexed easily. Tough as nails (metaphorically). Looking at the charts the process of hardening seems to favour specialists or very well controlled manufacturing.

I am looking forward to my next batch of home jobs, I changed the order so that the larger 6' blades are going to be done in 19c27. They will be hardened by a specialist. It appears that the 19c27 is tougher than 12c27 on the same rockwell, particularly over 58RC.

The others will remain 12c27 at RC57-58 so that the non knife-nuts can sharpen them.
 

knarfeng

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You might want to post this in the Maker's shop talk forum as well.
 
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Several knife makers had made the dealer examples in 4mm and I had a chance to test them (without destruction testing). The carving knife was 60RC and flexed easily.

How easily is "easily"? I'd expect any steel of just about any hardness to not flex particularly easily when it's 4mm thick.
 
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The difference in their three steels is for the most part carbon. 12C27 [.60 C], 13C26 [.68C], 19C27 [.95 C]. 19C27 will have more wear resistance not toughness.
 
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Whoops, I seemed to rush this when getting a chance on the internet between kids and wife doing WOW. A Chef's knife 9' long and very deep but ground to a V the whole depth and flexed considerably tip on the table the flat 45deg and my palm pushing on the centre. The 19c27 is app 1/3 more carbon and is tempered upto and including 60RC after freezer treating. The cryo treated blade gets upto 61RC on tempering.

The 19c27 takes 1-2RC > than 12c27 on the same heat cycle. So to get a the same RC the 19C27 needs a higher tempering cycle.

I am wondering what the trade off will be for a knife maker / knife nut, I always find there is a penalty.
 
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The trade-off for kitchen cutlery isn't so big. 19C27 and it's alloy-alikes are used in the more coveted Japanese-style chef knives from Misono, Suisin, Nenohi, and Masahiro and even used in the more affordable knives from Tojiro. The amount of coarse carbides isn't so large that it will interfere with sharpening (19C27 strops up very nicely) and the added wear-resistance more than makes up not being as tough as 12C27 or able to take as fine of an edge as easily as 13C26.

Cold Steel uses a similar alloy, VG-1, in many of there knives and the only complaint I've heard is that it's Cold Steel.
 
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