grinder wheel color

PapaChuck wrote:
> Hey --
>
> Am planning to decorate my garage and am wondering about grinder wheel
> colors ... shocking pink? ... dazzling white?? ... powder blue??? ...
> JUUUUSSTT KIDDING.
>
> But seriously, am starting to (finally) get serious bout sharpening
> (moving into woodturning) and am wondering about the difference between
> the blue, pink and white wheels. I assume they are all friable and
> will work OK at 3600rpm and much better at 1700rpm. What is the deal
> with the different colors??
>
> I humbly await The Blast.
>
> -- Chuck

Usually green refers to being carbide compatible. Gray is usually the
"junk" wheels that come with the grinder and are useful for grinding
off welding slag, etc. But other than these usual colors and purposes,
the color is just whatever pigment the manufacturer puts in the mix.
All grinding wheels are friable. They all will wear away, at different
rates. But its the level of friability that matters for whatever type
of steel/metal you are grinding away. On some metals you want a very
hard almost non friable wheel. On others you want a very soft very
friable wheel. As for whether wheels work better at 3600 or 1800, it
depends on how the wheel was made, etc. Oneway for instance talks
about this on their website. The slower speed is usually better for
the person because they have more time before they burn the steel. But
the actual cutting may be better at the higher speed. For woodworking
tools such as chisels and plane blades, high carbon tools, I think you
would want a fairly soft fairly friable wheel. For High Speed Steel
tools such as woodturning tools I think you want a harder and less
friable wheel than for carbon steel. Otherwise your HSS turning tools
would literally eat up the grinding wheel very quickly. And you would
have to use the diamond dresser to remove the grooves every time you
used the wheel. I doubt you will go too wrong if you buy a wheel
advertised by a woodworking supply store. They cater to the woodworker
and will almost certainly have fairly friable and soft wheels. May not
be exactly optimal, but will be close. May pay more than a comparable
wheel sold by an industrial supply store but wheels are not too
expensive.

[email protected] wrote:
> See http://www.pacificgrindingwheel.com/abrtraining/pdfs/training.pdf and
> http://www.georgiagrindingwheel.com/grindingwheels_basics.htm#faq2

These are GREAT resources. Thanx!!
-- Chuck

[email protected] wrote:
> PapaChuck wrote:
> > ... am wondering about the difference between
> > the blue, pink and white wheels.
>
> Usually green refers to being carbide compatible. Gray is usually the
> "junk" wheels that come with the grinder and are useful for grinding
> off welding slag, etc. But other than these usual colors and purposes,
> the color is just whatever pigment the manufacturer puts in the mix.

No, not exactly. Natural stone and ceramic wheels can come in
lots of colors, but Al2O3 (Aluminum oxide, ALOX, sapphire, corundum,
main component of emery- and maybe other names) is usually
manmade for these wheels, and pure white.

Pink is Cr-doped corundum (aka ruby), and is identical in grinding
properties
(unless the manufacturer uses the color to indicate binder or grit
differences).

Silicon carbide is green, man-made, and is widely used to grind
tungsten
carbide (W4C, Carbolloy, C-2, C-4, etc.). Hopefully no one uses green
coloring
to make lesser materials look like real SiC. This is the third-hardest
of
abrasives, below diamond (girl's-best-friend, cubic carbon, C) and
borazon (cubic
boron nitride, BN)

And the black/grey grinding wheels are what sloppy SiC manufacture
generates.
Who knows WHAT they use for binder/filler.

<[email protected]> wrote in message
news:[email protected]...
For High Speed Steel
> tools such as woodturning tools I think you want a harder and less
> friable wheel than for carbon steel. Otherwise your HSS turning tools
> would literally eat up the grinding wheel very quickly. And you would
> have to use the diamond dresser to remove the grooves every time you
> used the wheel.

Absolutely. Consider just how dumb turners can be to pay a premium in
initial cost and decreased useful life to get a wheel that "cuts cooler" to
sharpen HSS. Now carbon perhaps would benefit, but it's softer, so abrades
easier.

Which, BTW, is why AlOx gray wheels are not of necessity "junk," composed as
they are of the same abrasive used in the more expensive vanishing wheels.
If they don't cut metal as fast at the "friable" types, who cares? Turners
use their grinders for sharpening, not shaping. Doesn't that make a less
aggressive cut a benefit?

The basic colors are White, Pink, Green, Gray, Black and Blue.
I can say that Green is for carbide, White is soft and intended for HSS
cutting tools, Pink should be a little harder and Black and Blue are much
harder.
However this is not always true. Each manufacturers have their own
specifications associated with a color.
See http://www.pacificgrindingwheel.com/abrtraining/pdfs/training.pdf and
http://www.georgiagrindingwheel.com/grindingwheels_basics.htm#faq2


"PapaChuck" <[email protected]> wrote in message
news:[email protected]...
> Hey --
>
> Am planning to decorate my garage and am wondering about grinder wheel
> colors ... shocking pink? ... dazzling white?? ... powder blue??? ...
> JUUUUSSTT KIDDING.
>
> But seriously, am starting to (finally) get serious bout sharpening
> (moving into woodturning) and am wondering about the difference between
> the blue, pink and white wheels. I assume they are all friable and
> will work OK at 3600rpm and much better at 1700rpm. What is the deal
> with the different colors??
>
> I humbly await The Blast.
>
> -- Chuck
>