.

That's a BIG bar of shirogami!
At 6mm thick it has a lot of room to forge it out.
Think about how you will cut it up for knives. A section 20mmX150mm would forge out to a kitchen knife. 10mmX100mm would make a hunter.
Of course, it would also forge a katana, wakizashi, and tanto set if split into 1000X25, 750X15, and 250X15..

The main plus for shiro #1 is the low manganese. It is a great steel for a hamon. It is what is called a very clean steel because it has just about as little alloying as possible. There is less than .5% other elements besides iron and carbon.
It can be water quenched for maximum hamon activity, but Parks #50 works almost as well and is far safer to avoid severe warping or cracks.
 
Tamahagane and shirogane are different steels. The HT is similar, but tamahagane is almost always water quenched. Shiro can be either way. I prefer Parks #50.. Temperatures are close to the same.

300C is a very high temper. Not sure why you would do that with Shiro #1. I use around 395°F/200°C.
In the older thread you linked by HSC he was giving his personal process. He is a very skilled smith and has his own preferences. Not everyone does the same. Unless you are very experienced it is best to stick with the specs recommended by Hitachi (below). If the quench was done in water at the temperatures below, and the temper was at 200°C, I would expect the final hardness to be around Rc62. If done in Parks #50 I would expect Rc61.

Heat Treatment:
Annealing 740 - 770°C Slow cooling (760°C is good)
Quenching 760 - 800°C Water cooling (or Parks #50) (780-790°C is a good temp range)
Tempering 180 - 220°C Air-cooling (200°C is a good temper)
Delivery hardness (HB) 223 or under
Hardening hardness (HRC) 60 over (Higher with a 200°C temper)

HSC's tempering numbers are his preference. I highly recommend you doing a one-hour temper twice. Some of the things needed to temper very hard steel take time.

You mentioned making a box bellows and from your questions it looks like you plan on doing the HT by yaki-ire. That is fine but be aware that it takes a long time to learn to read the colors and temperature of the sword. You don't "know" the temperature, you are guessing at it. You will almost always be much higher than you think. Japanese smiths take years to learn yaki-ire ... with may failures along the way. Eventually, a smith at his own forge doing the HT the same way every time, under the same lighting conditions and on the same steel will learn to do it well.

Tempering on a charcoal fire is also non-precise. It is a bit more forgiving that the quench, though.
 
Forest Ninja said:
H HSC ///

Hello,

I noticed your thread here below and am a little confused about SHIROGAMI #1 and
am trying to find answers online despite most Westerners have not tried Japanese steels.

I have 2 questions below and hope you can answer them.

It seems in the thread below that you temper the steel at 356°F for only a short time.

laminated Hitachi White and Blue Steel Heat Treat Process

To help with the recent HT sticky, Im offering what I have learned and use myself relative to laminated Hitachi steel. I'll outline and detail the process as taught to me over about 9 days with Murray Carter over 2 separate visits. Carters book on bladesmithing is also a reference...
www.bladeforums.com www.bladeforums.com

I was under the impression that most steels were tempered for like 2 hours. I have watched many videos
of Japanese Swordsmiths temper a katana right after quenching at a reduced temp and quench again a
few minutes later.

Question #1:

Is this Shirogami #1 meant to be heat treated the same as Tamagahane once it's a blade?

Question #2:

I noticed a White Paper Steel tempering chart in fig.2 of the following pdf and was wondering
if tempering at 300°C would result in a 60 RC hardness. If so, would I be able to temper in
minutes vs a 2 hour tempering cycle?


Note: My SHIROGAMI #1 bar is in the 1st post of this thread.

Thank You,

Cheers
Click to expand...
This bar you have is laminated steel, correct? with mild steel cladding
In general, Stacy has given you some good advice and guidelines to go with.

Q1 - I don't have enough knowledge with Tamagahane to comment, sorry.
Q2 - I've never tempered at 300C so I can't confirm if that yields 60 RC, but that is what the spec sheet shows, so I would say it's probably accurate.
You can certainly temper in minutes but I would suggest you go with Stacy's suggestion of the 2x 1 hour cycles.

The only thing I can add is that previously I water quenched the Takefu laminated steels, but have now switched to a fast oil quench.
Lastly, while I do still flash temper the Hitachi laminated steels, I test the edge, if I find it's too chippy, I will temper again for a longer oven cycle,

You have enough steel to practice with and do some testing and I would suggest you do that.
good luck
 
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Forest Ninja,
I wanted to give you some advice from someone who has been around a while and seen a lot.

In the beginning, start simple. Use basic steels like 1075, 1084 , O-1, 1095, 5160, etc. Start with simple knives like a drop point hunter or a kitchen knife. Learn how to use the equipment you have to its best ability. There are people who use a small charcoal forge to forge, HT and temper a fantastic knife because they have learned how to use it to its fullest capacity. On the other hand there are people who have spent $10,000 on equipment and can't get a good result because they hop from one steel to the other and don't learn how to do the HT properly. The old adage is "100 Railroad Spikes", meaning make the same knife over and over until you master the forging techniques and HT. Railroad spikes used to be used to train a new smith because they were cheap and every one was the same size. Buying 20 feet of 1084 and making 40 drop point hunters at one a week would be a more modern rough equivalent of "100 railroad spikes". You will be amazed at how nice the 40th is compared to the 1st. In a year you could go from novice to experienced smith for very little cost beyond your time and close attention to learning the skills.

Starting with shirogame #1 isn't a good place to start. Heck, it isn't a good steel for anyone without a good bit of experience and fairly good equipment. It may be an expensive learning experience. I probably didn't use it until I had 10 years continuous experience at HT and forging.

I live in Norfolk, VA, USA and am 73 - everyone can see that by clicking on my avatar. They can see what I do for a living and what things I like to do for fun. We don't know a single thing about you.
While Forest Ninja may have seemed like a cool username to you, it sounds like the avatar of a kid playing video games. A real name or one that describes you would be a better choice. Best choice is your name (John Smith, J, Smith, Smith Forge, Tall Sam, etc.).
On the same lines, your location of "secret forest" is cute but offers no guidance to those trying to help you. We can't offer a shop visit, suggest local suppliers, or give advice in terms that you can use without knowing at least the country you live in. The city or area is even better. I used metric measurements on this thread because you used them. I'm guessing you are in the UK, or maybe Europe, because your specs are from a UK steel source for the Shiro #1, but for all I know you could be in the next city to me.
The same for not listing your age.

You should update your profile to give some real info and consider a name change (go to Tech Support for info on a name change).

Just friendly advice from someone who wants you to succeed.
Stacy E. Apelt, FSA Scot
 
Forest Ninja said:
Hello,

The bar is solid and not San Mai clad. :cool:

The plan is to make 2 blades with 1 being more than 3 times longer than the shorter of of the 2.
I'll do my initial testing with the shorter one and be sure to post what happens here when I do.
I have other types of steel like O1, 1084, W2, 26C3, Sheffcut and 1045 to play with before I try
anything with this Japanese steel.

Thanks for your time.

Cheers
Click to expand...
Interesting. I wasn’t aware Takefu offered a monosteel bar like that. In fact judging from the looks of your picture I’d be willing to bet it’s laminated. I can tell from the surface texture of the bar :) But I’ve been wrong before
 
I was thinking the same thing.
It looks like the site shows the same laminated drawing on all the Takefu steels. It is listed as available as mono-steel or clad. They state cold-rolled surface, so that may be why the surface looks like the laminated.
 
Harbeer,
Thanks for chiming in with your personal experience with this steel. Your knives are really nice and you have definitely refined your process. It is always best coming from "the horse's mouth".
 
Just to jump in with a possible correction, Takefu does not make shirogami 1 as far as I know, they appear to just be reselling core material that they buy from Hitachi that they use to make some of their prelam stock as well as using their own steel. I only mention it because the takefu core steels appear to be in some ways quite different from the Hitachi core steels. Aogami would also be from Hitachi.
 
Takefu doesn’t make steel, they are a hot rolling and laminating company. Their own unique steels are made by other companies for them. For example, Kobe also makes a version of Super Gold named R2. Takefu patented the steel so they are doing more than just rebranding steel but they don’t have the “steelmaking” facilities.
 
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