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I bought a set of HSS turning tools and I have a "white" Norton grinding stone on my (high speed) bench grinder.
I remember that in school we were taught to cool the HHS tools as we ground them to keep them cool.
This morning I was reading on this website (http://yarchive.net/metal/hss_grinding.html) the recommendations of this guy who say to never cool HSS tools as they develop cracks due to the thermal shock and to grind them "Hot" until they reach a dark red color, applying quite a bit of pressure on the grinding wheel.
What is your opinion about this?
Also this morning I was looking a system similar to the the Tormek system (low speed + water cool ) but for a fraction of the price to sharpen my planes and chisels. Would this work for HSS tools also or is the stone too soft too for HSS ?
I am also looking at the Veritas sharpening jig, does any one of you have experience with it?
Thank you for your replies.
Bert
 

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You've probably read that a slow speed grinder is better for sharpening turning tools. That is true, but you can get by with a regular speed (3450 rpm) grinder if you have to.

HSS tools do not loose their temper if they overheat some (with some blue showing on the metal). However, I never overheat them too much. I would never heat them until they have a dark read color. My tools usually have a little bit of blue showing.

I've heard that you should never cool HSS with water. Let them air cool.

I personally prefer a slow speed, 8", grinder and the wolverine system. Many of us considered this the standard for sharpening lathe tools. You will also want the vari-grind jig for sharpening bowl gouges with the fingernail grind.

The key is consistency. You want your tools angle to the grinder wheel to always be the same. I can talk a little more about how to do this if you send me a private message.
 

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Bert,

Don't believe all you read as there is a fair amount of BS floating around and sometimes it's hard to sift truth from the rest.
HSS can be cooled in water, that's what they do when they use it in turning metal at high speed of cut and substantial chip removal you do not want the cutting tool to get too hot (If it changes color it is already too hot) soo they run a cooling stream of water, water mixed with cutting oil (It turns the water milky white) or oil.
As stated above do not overheat the HSS, also you can use a regular grinder with your Norton wheel to sharpen your tools.
My experience comes from my dad's machine shop, true they nowdays dont use HSS for cutting tools any more but many years ago it was state of the art and from time too time they still use it.

As an aside my dad used to fabricate turning tools for a large furniture manufacturer and he would buy HSS in the untempered and annealed state so that he could cut it in the milling machine and he used to tell me how unforgiving a material it is. You see HSS hardens as soon as a critical temperature is reached (you don't have to quench it in water or oil as Carbon Steel does) and it's almost impossible to return it to a workable hardeness once that happens, unless you have some very specialized equipment.

Also if you can see the metal glow from the heat applied you are already at the cristalline recomposition state and you can weaken the metal as you don't have control of what's going on internally. Keep the tempearture of your tool to a manageable state (If too hot to touch) it's too hot, make short passes and cool frequently.
You will get more mileage out of them….

Have fun….
 

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Yes don't wet cool after sharpening with hss steel.be sensible and don't get the metal glowing in the first place speed is not a requirement when sharpening if you want to have your tools last a long time then take your time.It's ok for carbon steel though.Alistair
 

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Been a toolmaker for 33 plus years - if a person grinds a tool on a pedistal grinder go slow - when the metal gets warm to the touch just dip it in a "soup can" full of water - as long as the tool doesn't get hot enough to turn "blue" you will be just fine - once tool steel turns a dull red color you are approaching the point where it begins to loose its hardness and begins to soften. After you get the edge "roughed in" then you can hone it down with a combination stone to achive a razor sharp edge if needed. A slow turning grinder will work but for the average person it is unnecessary
 

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I don't believe in grinding to sharpen. Grinding should only be done to get the original bevel…or to repair a tool that has been knicked or damaged.

To sharpen…there are many methods…all of them work…some of them are easier then others. I use a diamond stone and a leather strop. I also have some whetstones and some Japanese water stones. I use them for different purposes. To keep my lathe tools sharp…I will stoke them over a diamond stone a few times on each side….until they feel sharp. I then strop them over a leather strop with diamond compound. That is good enough to put a very sharp face on any lathe tools….for the curved goughes I use a diamond stone for the outside…and then stoke a round diamond (Called a chef knife sharpener) sharpener over the inside curve….then strop….

You can use a strop often to keep the tool sharp…when it begins to dull quicker…back to the stones…then strop.

Using stones (diamond or ceramic) is probably the best shapening system….doing it by hand is not that difficult to learn and to do….and it is sure much less expensive then the grinders and sharpening systems….Don't get me wrong, those systems do work and some are not bad….but you can get the same or better results with a stone and a strop.
 
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