MatthewZS
Member
Anyone have any reasons why a seldom used tool couldn't be re-ground into a more often used "configuration"?
Thanks.
Thanks.
Just make sure to keep a bucket of water handy so you don't overheat the tool and ruin the temper!
Just make sure to keep a bucket of water handy so you don't overheat the tool and ruin the temper!
I've heard that dousing the tool in a bucket of water to cool it down actually stresses the metal and decreases the strength of it. Advice I've been told is to let the tool come to a resting temp from grinding then rework it again.
Just make sure to keep a bucket of water handy so you don't overheat the tool and ruin the temper!
Just make sure to keep a bucket of water handy so you don't overheat the tool and ruin the temper!
I've heard that dousing the tool in a bucket of water to cool it down actually stresses the metal and decreases the strength of it. Advice I've been told is to let the tool come to a resting temp from grinding then rework it again.
Just make sure to keep a bucket of water handy so you don't overheat the tool and ruin the temper!
I've heard that dousing the tool in a bucket of water to cool it down actually stresses the metal and decreases the strength of it. Advice I've been told is to let the tool come to a resting temp from grinding then rework it again.
I have also read and been told that dousing tools causes stress to the metal and that HSS metal can't get hot enough on a grinder to cause it to lose it's temper. I regrind shapes a lot. I buy tools at garage sales and then regrind them into whatever shape I want.
Pete is correct here. HSS is designed to get hot, and quenching it cracks the steel and weakens it. If you need to cool it, quench the handle end, not the cutting end of the steel.Heating carbon steel without quenching until it begins to turn colour softens the edges. High speed steel was designed to cut metal until very hot without loosing its hardness. Pretty much all the turning tools these days are high speed steel. When you quench high speed steel when hot they form micro crystalline cracks at the edge which results in them breaking down faster. They get dull. :wink:
So quench the carbon steel often before they get hot. Don't quench high speed steel.
To reduce or prevent the steel from getting hot in the first place use the correct wheels for sharpening and dress them often.
Pete
Pete is correct here. HSS is designed to get hot, and quenching it cracks the steel and weakens it. If you need to cool it, quench the handle end, not the cutting end of the steel.Heating carbon steel without quenching until it begins to turn colour softens the edges. High speed steel was designed to cut metal until very hot without loosing its hardness. Pretty much all the turning tools these days are high speed steel. When you quench high speed steel when hot they form micro crystalline cracks at the edge which results in them breaking down faster. They get dull. :wink:
So quench the carbon steel often before they get hot. Don't quench high speed steel.
To reduce or prevent the steel from getting hot in the first place use the correct wheels for sharpening and dress them often.
Pete
Carbon steel is the opposite, it looses harness when heated, this steel is better kept cool when grinding, it is tricky to recover the hardness after carbon steel is heated.
The mechanical and thermal properties of steels is a complex subject, huge textbooks are written on the subject of steel.
Here is a decent discussion on grinding HSS on a machinist forum:
http://www.practicalmachinist.com/vb/general-archive/grinding-hss-hot-89869/
Here is a short discussion on the properties of HSS:
http://www.ehow.com/list_6128773_physical-properties-high-speed-steel.html
Can any of you "metal guys" tell me: Is there a difference in quality among HSS edges?
If I buy a "name brand" HSS, is it likely to be BETTER than a cheap HSS?? If so, what is the difference?
Thanks for any input--I have often wondered about this.
Can any of you "metal guys" tell me: Is there a difference in quality among HSS edges?
If I buy a "name brand" HSS, is it likely to be BETTER than a cheap HSS?? If so, what is the difference?
Thanks for any input--I have often wondered about this.
I remember hearing better HSS tools (brand names)are tempered through the entire tool while cheap HSS tools are not. Don't quote me on this it's just something I remember. On the side note being a cheap New Englander I use HF lathe tools:biggrin: @ somwhere $45.00 for a whole set
Can any of you "metal guys" tell me: Is there a difference in quality among HSS edges?
If I buy a "name brand" HSS, is it likely to be BETTER than a cheap HSS?? If so, what is the difference?
Thanks for any input--I have often wondered about this.
We are getting deeper into those steel textbooks here.Can any of you "metal guys" tell me: Is there a difference in quality among HSS edges?
If I buy a "name brand" HSS, is it likely to be BETTER than a cheap HSS?? If so, what is the difference?
Thanks for any input--I have often wondered about this.
I remember hearing better HSS tools (brand names)are tempered through the entire tool while cheap HSS tools are not. Don't quote me on this it's just something I remember. On the side note being a cheap New Englander I use HF lathe tools:biggrin: @ somwhere $45.00 for a whole set
Heating carbon steel without quenching until it begins to turn colour softens the edges. High speed steel was designed to cut metal until very hot without loosing its hardness. Pretty much all the turning tools these days are high speed steel. When you quench high speed steel when hot they form micro crystalline cracks at the edge which results in them breaking down faster. They get dull. :wink:
So quench the carbon steel often before they get hot. Don't quench high speed steel.
To reduce or prevent the steel from getting hot in the first place use the correct wheels for sharpening and dress them often.
Pete
Carbon steel is the opposite, it looses harness when heated, this steel is better kept cool when grinding, it is tricky to recover the hardness after carbon steel is heated.
If you get your carbon steel tool too hot and it has lost it's temper.....you can re-harden the tool without too much effort.
Once you have the shape you want on your tool you can harden the steel by taking a torch to it and get it to an even color.....you're look for a 'Straw' color. When you get this color immediately quinch the tool in a can of oil....you can use cooking oil (crisco) if handy.....once used, it's yours, momma won't want it back in the kitchen! When you quinch the tool, keep it moving in the oil until you can handle it. If you did everything right, you can take a file to it and it won't mark the tool.
Have fun and be safe!
Barney
The $45 set is likely high carbon steel.
"Once you have the shape you want on your tool you can harden the steel by taking a torch to it and get it to an even color.....you're look for a 'Straw' color. "
I have always had to get the steel to an even medium red -- a common test is the point were a magnet no longer will attract the steel.
Plunging the red hot steel into the oil/water/ or air cooling (depending on the steel) will cause the hardening.
The "straw color" is a smiths guide to the tempering of the hardness to reduce brittleness. I just use the oven at about 375 degrees F and do not try to read the color.
I stand corrected, thanks.The $45 set is likely high carbon steel.
They ARE indeed HSS and make for a very decent starter set!
http://www.harborfreight.com/8-piece-high-speed-steel-wood-lathe-chisel-set-47066.html
I can very much appreciate this thread as a newbie to this trade. I have some background in engineering ,but not to this extent, However, I have a qsn. about some Sorbey tools I have aquired recently frm a freind who's dad was a turner, and I can not tell which one of these metals I've got on these tools. All it says on the shanks of these tools is shefield metal which doesn't tell me what it is. In addition, I am sure that these tools are not very recently made, would any of you can tell me what I ahve and what's the best way to recognize them or do I need to post pic.s of them for you to see?
Thanks.
The $45 set is likely high carbon steel.
They ARE indeed HSS and make for a very decent starter set!
http://www.harborfreight.com/8-piece-high-speed-steel-wood-lathe-chisel-set-47066.html