Thread: The best heat treatment for Suminagashi Steel

Originally Posted by Bruno

That could very well be. In that case you could use a deep fryer to preheat the oil and quench in that.
In any case, no matter how you quench, the difference between the mild steel sides and the 1.3% carbon steel core means that there is always going to be the risk of a violent split.

I agree. After I posted I was thinking that this is not really the same thing as quench cracking in a single alloy steel. It still makes sense to make the tail end of the quench as gentle as possible though.

I have done several razors now in Suminagashi and I heat up my medium speed quenching oil (same I use for 01) to 80c. No cracks, splits or anything. It has been flawless so far. This MO works great for me.

I tested quenching with A. a faster quenching oil (Parks 50) and B. with lower temps using both fast and medium oil (50C and 60C) and I got cracks towards the edge.

That settles it then. I probably quenched too cold. I'll have to buy a cheap fryer and mount it my quench tank

Originally Posted by Maximilian

I have done several razors now in Suminagashi and I heat up my medium speed quenching oil (same I use for 01) to 80c. No cracks, splits or anything. It has been flawless so far. This MO works great for me.

I will try with canola oil. Thanks!

Originally Posted by Bruno

I'll have to buy a cheap fryer and mount it my quench tank

Bruno, that's what I do. I also use a separate digital cooking thermometer to double check the temp as the thermostat from those fryers are usually not very accurate.

I've been heating my oil in a double boiler set up and using a candy thermometer. The double boiler works well in that I can also easily cool the oil with a bath of cool water if I get it too warm.

When Quenching I use a dual read out Thermo couple
1 in my forge & 1 in my oil

Nice setup, thank you for sharing!

Okay so I went to customer service and got response next day :<0)
Thank you very much for your inquiry.

The item comes with instruction:





Best regards
Customer Service

Update!

I maked a kamisori and everything was perfect. The grindig was difficult as Bruno said. I am pleased with the results. I got fine and sharp edge. Thank you for your help!

My process:
I leaved 1.5 mm thikness of the edge.
soaking: 805C / 1480F, 8 min.
quenching oil: 80C 20 sec - Thanks Maximilian
tempering: after cooling to room temperature, 210C 2x1h (between cooling to room temperature)
After this I sanded a few tenths of millimeters from the edge.