Blister steel (carburized wrought iron)

[J W Bensinger]

Has anybody else worked with this stuff? I've done four blades over the years-a chef's knife, a bowie and this hu die dao, which is the only one I've done a good etch on:

This thing was groun edge to spine, so none of that is grinding marks-it's all grain.
The pieces I've used had to be drawn to almost bright blue to get them to stop chipping on a brass rod, so the carbon content is right up there.

 

[GHEzell]

I've used a bit of it, sourced from old buggy springs. I do a lot of historic blades, so it is perfect for that. I've found that it has a surprisingly high austenizing temp (higher than I was expecting anyway), needs a very fast quenchant, and the edge holding is a little disappointing compared to modern steels. I'm pretty sure no two pieces are exactly alike chemistry-wise, just as no two pieces of wrought iron are. A long slow etch really brings out the beauty of it. I wish I had more of it, I might have enough for 3 more blades....

I've been reading up on how to make it, and plan to try this summer.

I believe what we both have is actually shear steel, which is a more refined version that has been folded and re-welded to itself a few times to help equalize the carbon.

Here are two blades I've made out of it...

 

[J W Bensinger]

The only one of the three blades I did that gets a lot of use is the chef's knife-the other two are fighters so other than the occasional sapling or tatami omote they don't cut much.
The chefs knife holds an edge pretty well, but I did not temper it back as far as the others.
The bowie might well be shear steel-I regularly forget that name...but the Hudie Dao is blister steel.
I think I might have another 3-4' of 1-1/2"x5/16" spring left, at this point.
Love to hear how the making of it goes!

 

[islandblacksmith]

i am a big fan of shear steel because it is the closest thing to pure simple carbon steel around (other than hitachi white paper steel)...very few modern steels have such low alloy content, and most have so much manganese that they will not shallow harden (most historical hamon patterns cannot be reproduced in deep hardening steels)...but there is quite a range in quality to be aware of, the main divisions after blister steel (which is straight out of the carburizing sarcophagus) are single, double, and triple shear steel which indicate the number of times the stack was forge welded back on itself (each time refining the grain* and carbon distribution)...

hard to find, like treasure to me...nice work!


*not grain as in steel crystal but "grain" as in wood grain, because they were starting with wrought (bloomery) iron as the base material which has a definite wood grain structure caused by large inclusions of silica/slag.

 

[J W Bensinger]

I forgot about this one-same buggy spring stock: