Japanese Bowl Turning

[Bill Alston]

Leaf and coil springs from vehicles are used a lot for edge tools.
I saw a basic Blacksmiths guide intended for the third world many years ago and all the tools were made from it.

Silver steel rod is commonly available over here as is ground flat stock. Both are good for edge tools. I recently milled a beading tool from Silver steel and it works well. I tempered the whole tool to help prevent it snapping in use. I frequently though leave the very tip of cutting tools “glass hard” and I’ve not had any issues. Some high carbon tool steels have a Rockwell hardness similar to HSS if left like this. They don’t have the wear resistance of HSS but for some tools this isn’t too much of an issue.

This is the Beading tool.

 

[Rabea Gebler]

I was taught both how to make tools from carbon steel as well as HSS, the carbon we mainly use for Greenwood. Most Japanese lathes can operate around 2000rpm. Especially with scrapers, the carbon steel does not cut nearly as well as the HSS. Because the scrapers often have a difficult shape to forge, we sometimes forge the tool handle from mild steel and braze a plate of HSS steel to the mild steel with some melted copper; this cuts miles better than carbon steel - not quite comparable. As to how proper or not the heating process is, I can't say, but it is the way that I was taught at the wood-turning school, and the blades get super sharp. It is also quite evident if a tool wasn't heated high enough. It might not be the proper way, but the results are good

I temper according to colour but it is likely something like this:
Forge around 1000°C plus
Stress Release: reheat at around 600°C and let air cool slowly
Hardening: Bring the steel back up to super white colour, just before it "sparks", then quench in oil or water and let air cool

Here is a pole lathe turner who came to Japan a few times to study some of the techniques and also forges HSS hooks: https://www.woodspirithandcraft.com/shop/highspeedsteel-turning-hook

 

[Rabea Gebler]

Japanese-style woodturning on a Western Lathe.

View attachment 59740

Can I ask where this picture and one of the tools were taken? I am very curious because the Toolrest looks like it was made by someone I know and the tools look Yamanaka Style as well, looks like the same steel and Handles which I use

 

[Bill Alston]

The carbon steel does not cut nearly as well as the HSS.

I find this curious. I worked with a guy who before becoming head of the technology department at a school, took a degree in Metallurgy and worked in industry. He explained to me why high carbon tool steel can take a sharper edge than HSS. It was some years ago but the salient point as I remember it was that high carbon steels have a finer grain structure.

Can I ask where this picture and one of the tools were taken? I am very curious because the Toolrest looks like it was made by someone I know and the tools look Yamanaka Style as well, looks like the same steel and Handles which I use

I’ve no idea. It was a screen shot, since deleted on my iPad. Try a reverse image search, something may come up?

 

[Rabea Gebler]

You are absolutely right that high-carbon steel gets sharper, but it doesn't hold an edge as well as HSS. When I turn dry hardwood on a fast-spinning machine, I aim for sharpness with long-lasting edge retention, which makes the HSS "cut better." This is also why I would choose carbon steel for greenwood: It is sharper. When it comes to the scarpers, the burr with HSS lasts longer and cuts much better, but I am not sure why that is. Either way, I am no expert in Metallurgy and can only speak of what I was taught and have experienced while using my tools. There might be better steel options and definitely better ways to harden the tools, but in my experience, my HSS tools work great for the intended use

 

[John Snow]

Maybe not so relevant to the technical discussion here, but it seems to me that the style of turning in these videos is born of a craft culture relatively poorer in money than in modern Western-style turning. For example, lathes are very simple, and seemingly shop-made, as is the associated equipment, bench, toolrest, no fancy toolholders, etc. The cutting tools are generally hand-made by the turner from a very limited selection of round stock, while Western tools come from all manner bar, round, and flat stock. The cutting ends are continually forged and sharpened as needed, mostly by hand, with very little help from a cheap bench grinder. While Western turners are advised to use sandpaper as though it were free (it sure isn't!) these Japanese turners use scraping techniques with just a tiny bit of sandpaper for final cleanup. Basically, these videos are showing production techniques from a time when money was scarce and the industrial base was smaller than now in Western-style turning culture.

 

[Neil S]

Maybe not so relevant to the technical discussion here, but it seems to me that the style of turning in these videos is born of a craft culture relatively poorer in money than in modern Western-style turning. For example, lathes are very simple, and seemingly shop-made, as is the associated equipment, bench, toolrest, no fancy toolholders, etc. The cutting tools are generally hand-made by the turner from a very limited selection of round stock, while Western tools come from all manner bar, round, and flat stock. The cutting ends are continually forged and sharpened as needed, mostly by hand, with very little help from a cheap bench grinder.

.
John

What your analysis isn't picking up on is the respect that Japanese culture has for their traditional crafts. What you are seeing isn't a failure to adopt more 'modern Western-style turning' techniques and equipment, but rather a treasuring of of their traditional crafts and a commitment to maintain those traditions. The masters of this craft (as is the case in many other traditonal crafts in Japan) are designated as 'National Living Treasures'...

Living National Treasures in Lacquerware and Artworks｜Gallery Japan

Introducing information on Living National Treasures of lacquerware and their excellent artworks (lacquerware, letter boxes, etc.). One of the largest craft sales websites in Japan, Gallery Japan

www.galleryjapan.com

This sensibility may be foreign to us in the West, but shouldn't be misread as an impoverished tradition from the past that has failed to keep up with 'modern' Western-style turning, but a valuing of a traditonal Japanese craft and aesthetic.

I could go on, but won't labor the point.

 

[Neil S]

You are absolutely right that high-carbon steel gets sharper, but it doesn't hold an edge as well as HSS. When I turn dry hardwood on a fast-spinning machine, I aim for sharpness with long-lasting edge retention, which makes the HSS "cut better." This is also why I would choose carbon steel for greenwood: It is sharper. When it comes to the scarpers, the burr with HSS lasts longer and cuts much better, but I am not sure why that is. Either way, I am no expert in Metallurgy and can only speak of what I was taught and have experienced while using my tools. There might be better steel options and definitely better ways to harden the tools, but in my experience, my HSS tools work great for the intended use

HSS is definitely the better way to go for the reason you give (ie edge retention) and if you have been taught a way of heat treating in your workshop and it works then you are ahead of most of us!

As far as I'm aware, there won't be any better steel options or heat treatments that you will be able to do yourself with the equipment you are likely to have in a regular workshop.

So, many thanks for sharing your HSS heat treatment method.

 

[John Snow]

.
John

What your analysis isn't picking up on is the respect that Japanese culture has for their traditional crafts. What you are seeing isn't a failure to adopt more 'modern Western-style turning' techniques and equipment, but rather a treasuring of of their traditional crafts and a commitment to maintain those traditions. The masters of this craft (as is the case in many other traditonal crafts in Japan) are designated as 'National Living Treasures'...

Living National Treasures in Lacquerware and Artworks｜Gallery Japan

Introducing information on Living National Treasures of lacquerware and their excellent artworks (lacquerware, letter boxes, etc.). One of the largest craft sales websites in Japan, Gallery Japan

www.galleryjapan.com

This sensibility may be foreign to us in the West, but shouldn't be misread as an impoverished tradition from the past that has failed to keep up with 'modern' Western-style turning, but a valuing of a traditonal Japanese craft and aesthetic.

I could go on, but won't labor the point.

Sorry if I gave the impression I was criticizing their methods. I was just comparing. We in the Western tradition certainly have adherents to the earlier methods before money was as abundant as it is now and before the industrial base was as developed to supply a vast variety of tools and tool-making stock. What these bowl-turners are doing is amazing to me, a bodger who needs lots of sandpaper to get a good surface instead of a bit of recycled saw blade for a scraper.

 

[Alan Weinberg]

What these bowl-turners are doing is amazing to me, a bodger who needs lots of sandpaper to get a good surface instead of a bit of recycled saw blade for a scraper.

Very true. A bit of thread drift—we visited Japan pre-Covid and were amazed at the integrity, dedication, desire, and performance of people at every level of job—each wanted to be the absolute best at what they did—even if it was a menial task such as sweeping the sidewalk. One street vendor making omelets made each one perfectly, focusing all his attention on achieving the best he could, much like the turners producing identical bowl after bowl. Tradition was respected even while progress was being made, and it was a revelatory experience I’d love to repeat. The culture there is amazing.