Hitachi White/Blue info

[Stacy E. Apelt - Bladesmith]

Dictum just sent me a copy of the info on these steels. I had to copy it as a photo in three pieces.

I'll try and convert it to pdf later.

 

[Dopic1]

Thanks for posting this Stacy!

 

[Stacy E. Apelt - Bladesmith]

I put it in a pdf file. Just click the attachment, open file, print. Also added to stickys.

 

[Robert Erickson]

Thanks Stacy. I have some laying around that I've been wanting to use, but a little afraid of because it's so temperature sensitive after HT.
It says to fully profile and grind the blade before HT...so go all the way down to 0.007 to 0.01 pre HT?

 

[Stacy E. Apelt - Bladesmith]

NO, they mean to fully PROFILE the blade, grind all edges smooth, drill all holes, and remove any deep scratches. The basic bevels can be ground in on thicker blades, but keep the edge at .030". On any blade below .100", I would just profile, harden, and grind the bevels post HT.

If going for a hamon, grind the bevels and sand to 400 grit. Leave the edge at .030-.040", depending on how big the blade is.

 

[HSC ///]

This specific model of the hitachi is for forging only, correct? Not for straight stock removal. That's my understanding from the dictum specs. Pls advise.

 

[Matthew Gregory]

No such thing. If you can forge it, you can grind it.

 

[Stacy E. Apelt - Bladesmith]

No, actually, the blue and white steel is very good for stock removal. Forging can mess it up and end up a waste of money. For a kitchen knife or any normal size blade, these Dictum steels are the way to go for stock removal folks.

 

[HSC ///]

ok so just so I completely understand...
this is a laminated steel? with a high carbon middle core? and "Outer layers with low carbon content"

thanks

 

[samuraistuart]

Yes, the info Stacy posted is in reference to the laminated San Mai blades that Dictum sells. IIRC, tho, they also have mono steel shiro and ao if you would like to forge some out.....https://www.dictum.com/en/materials/steel/steel/719620/white-paper-steel-from-japan?ffRefKey=ztR8t_EoB

 

[jdm61]

The thickness of stock that we can get and, in the case of the white and laminated from Dictum and WSH, the width, says that if you want thin kitchen blades, you are going to have to move some steel around with a hammer or, in the case of the Aldo sourced blue, thin it out a bit on the grinder. For Metric sized steel, 2.7 mm stuff is about as thick as you need for stock removal double beveled kitchen blades.

 

[Stacy E. Apelt - Bladesmith]

The data sheet is for blue steel and white steel. These are mono steels. They are often used as core material for high end laminated blades.

There is one side note pertaining to the laminated steel from Hitachi. The laminated steel is worked at the core steel values.

 

[Atlas Knife Company]

Any experience on hold time for HT? It doesn't say in the sheet.

 

[Dopic1]

Any experience on hold time for HT? It doesn't say in the sheet.

From what little information I have been able to find it's saying soak for five minutes 1470 to 1500 F and quench in brine or warm fast oil like a Parks 50.

 

[jdm61]

You need to be kind of careful about "warming" Parks #50. The top end of its temp range is 120F and as best as i can tell, it doesn't appear have that mid range "sweet spot" like the Houghton/Toughquench stuff does at 150F. . It is a "room temperature" quenchant.

From what little information I have been able to find it's saying soak for five minutes 1470 to 1500 F and quench in brine or warm fast oil like a Parks 50.

 

[GHEzell]

The white paper steel: No manganese at all... interesting.

 

[Stacy E. Apelt - Bladesmith]

Soak time is as with other hyper-eutectoid steels - 5 minutes.

The white paper steel has little or no Mn. It is very shallow hardening, and excels at a hamon. Blue has a tad more alloy, and is easier to HT.

As pointed out, do not warm up Parks #50. It is a room temp quenchant.....70-90F is where it is best.

 

[stezann]

I have not used this steels, but care is to be needed with those soak times.
If the steel is made intended especially for forge welding use, it is not necessarily ready to quench, so to speak. And it may require some normalization+grain refinement before said straightforward heat&quench.

The Hitachi mill would skip altogether all those refining steps if their main customers were going to welding temperatures anyway, as is the norm in Japan with their mainstream laminate blades.
Does it make sense?

Stefano

 

[Dopic1]

You need to be kind of careful about "warming" Parks #50. The top end of its temp range is 120F and as best as i can tell, it doesn't appear have that mid range "sweet spot" like the Houghton/Toughquench stuff does at 150F. . It is a "room temperature" quenchant.

Soak time is as with other hyper-eutectoid steels - 5 minutes.

The white paper steel has little or no Mn. It is very shallow hardening, and excels at a hamon. Blue has a tad more alloy, and is easier to HT.

As pointed out, do not warm up Parks #50. It is a room temp quenchant.....70-90F is where it is best.

Thanks Guys,:thumbup: I was not aware that Parks 50 was a room temp quenchant. I have very limited experience with this and was just repeating what I read. I have a small piece of Blue # 2 and very interested to try it and see what the results are.

 

[Atlas Knife Company]

XXX --- incorrect data removed --- XXX

I've updated my baseline HT chart to include these steels. To reiterate, the chart is baseline only to give a starting point. Do NOT consider it a replacement for a known HT recipe.

From what little information I have been able to find it's saying soak for five minutes 1470 to 1500 F and quench in brine or warm fast oil like a Parks 50.

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