Thread: Iwasaki Tamahagane Information

Okay. Here we go. Rather than write a long essay, I'll make a list of points why I think the Iwasaki tamahagane razors are so special.

1. Exceptional craftsmanship. This encompasses a lot of things. The most notably, the care taken to do things well. Iwasaki took the time and effort to do things like hardness testing. Doing a micro-hardness test on a finished razor is extremely difficult. Most likely, they took the time to prepare a metallurgical sample for each steel and heat treat batch. My procedures are probably pretty similar. It takes about an hour to make and polish a sample for micro-hardness testing. Also, the grinding and evenness of the honing bevel is wonderful.

2. Doing something difficult. Traditional forge welded tamahagane usually has too many Silica inclusions to make a good razor. To provide consistency in his steel, Iwasaki took the time to melt the tamahagane in a crucible. This is a complex process as well. This removed much of the Silica. What was left became so small as to be inconsequential. With traditional forge welded tamahagane, every batch can be quite different in Carbon content, Silica content, and other properties.

Tamahagane is very "fussy" in heat treatment. Even the best Japanese smiths lose about 30% of their blades, due to cracking during heat treatment. Most of us have seen the photo of Iwasaki's scrap pile. Those blades most likely cracked during heat treatment. Yet, they were kept, most likely for re-melting. The commercial steels of the time could have been hardened in oil, eliminating the cracking problem. A tamahagane razor was worth the cost of losing about 30% of his production. All of this during a time when straight razor popularity was decreasing!

3. Melding the ancient with the modern. This is an area where one could wax poetic for hours. Iwasaki took the best from ancient Japanese steel making and melded it with modern metallurgy to produce an exceptional product.

4. Unique functional properties. The most notable is the low abrasion resistance of tamahagane. It is possible to keep an Iwasaki tamahagane razor sharp for a very long time, with just canvas and leather stropping. This is amazing. The closest modern steel would be 1095. But, it's not the same at all. 1095 has a much higher abrasion resistance, at the same hardness. I'm hoping to work with a local metallurgy lab, to quantify some of this. If you ever have the opportunity to hand sand a piece of hardened tamahagane and a piece of hardened 1095, the difference is easy to feel.

5. Limited availability. Supply and demand...

I don't think the honing angles are anything special. My guess is Iwasaki simply found the angles that worked best with his steel and heat treatment. Seeing this does tempt me to tinker with my Timahagane honing angles.

I'm sure there is more I will come up with. But, this is a start. Studying these razors and their makers has shown me the potential of what can be achieved with ancient steels. It is certainly motivation to get out in the shop and smelt some steel.

More to follow...

Tim Z.

Originally Posted by FatboySlim

Tim, I don't want to put you on the spot, but I'd think that all of us would love to hear exactly why you think the Iwasaki tamahagane is so special. You're in a pretty unique position as a no-shi!t razorsmith who makes his own steel to tell us what is so special about Iwasaki razors, beyond the interesting HRC values.

It's unlikely I'll ever own one. But living vicariously through you, it would be nice to have a detailed insider's take.

(I met you years ago at an SRP meet-up in Asheville, NC, and you were gracious to me and everybody else, answering every question we all had. It was great, a very fond memory.)

So let's start with the 19 degree bevel angle (!?) and just work back from there, in glorious detail.