What steel for Making your own woodturning tools?

[Sisyphus]

I have been buying all the usual types of HSS gouges and chisels for years and sharpening them on an 8 inch Record Power grinder which runs at 2800rpm. I recently treated myself to a CBN wheel and have been getting excellent results from it.
I saw a video on YouTube about making your own tools and as I wanted a non standard scraper I thought I would make one. I went to a metal supermarket today and asked for some flat HSS bar. This was a new one for them and when I explained what I wanted they gave me a short piece of what they called Tool Steel to see if it worked.

I set the platform to the right angle and touched the wheel. It worked fine for a second or so then seemed to dig into the wheel and flew up in the air. I tried again, even more gently, with the same result. I finally managed to get an edge on half the depth of the bar and it cuts like a dream but it was more than a little nerve racking. I then tried one of Mr Sorby's scrapers and there was no problem.
I am wondering if the steel is too hard or the grinder is too fast or if I should clamp the steel to the platform.

Does anyone have any experience of making their own tools and can give me some help? There is a considerable financial benefit in making my own tools but the risk of a heart attack seems fairly high.

 

[CHJ]

The 'Tool Steel " will no doubt be in an un-heat treated 'soft' state to allow easy working, suspect that's why it grabbed on the CBN wheel.

To keep its edge after shaping it would require Hardening, (heat to Cherry Red and quench) and Tempering to remove brittleness (polish, heat to Dark Straw/Brown colour and quench)

 

[J-G]

Since you went to a 'metal supermarket', the chances are that what you have is too SOFT rather than too hard.

As far as I know, Metal Supermarkets only stock raw steel - be it 'tool' steel, or any of the various free-cutting (En1a) or the higher carbon EN8 etc. so what you have should be machined to the shape needed and then hardened and subsequently tempered.

This may be possible by simply heating it with a blow torch and then quenching in oil with a further treatment to a lower temperature but without knowing the exact specification it's impossible to say.

In its current state you could probably put an edge on it and do some scrapping but I suspect that it wouldn't keep its edge for very long.

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#-o
I see that CHJ has posted a more detailed reply while I was typing.

 

[woodpig]

It's probably 01, sometimes called gauge plate or ground flat stock. Less likely is D2 which is another common "tool steel".

Looking at their website they have information on about 7 different tool steels but can't seem to see which ones are kept in stock. Not the most useful of websites I've come across.

 

[woodfarmer]

If you can't find ready to use hss try EN36. Note this is a case hardening steel and is fine for light use scrapers. this is because when you sharpen them the soft centre isn't used for cutting, only the top outer skin which is hard is used. Be aware this will prevent you from making a skew chisel or any negative rake edge.

Harden by heating in a charcoal burner (BBQ). take your time let it stabilise and stay hot for at least half an hour. then cool in oil. do not hold it in the oil until cold, pull it when about 150-200 C Not easy to guess but a wet tissue should boil but not singe. then let it air cool.

Most case hardening steels will work. don't over do the cooling. it is better that they bend rather than snap.

If you really want to get technical, try Damascasizing the end of a bit of bar

Hope this helps..

 

[Sisyphus]

Many thanks for the helpful replies. I'm not sure where there is a thanks button for individual thanks so apologies for clogging up the system.
Never tried hardening and tempering before but I'll give it a go.

Mod edit:-