New metals and old methods

[Scott Ticknor]

When I started turning 30 yrs ago at work , we still used high carbon steel.High speed steel came along and changed everything for the good. I used aluminum oxide wheels with good success.Nothing like a tool right after sharpening With the new steels available, I thought I might take the jump. My question to those in the know is can I use my alum-oxide wheel to sharpen them or do I need a CBN wheel to get the most out of these tools .

[John K Jordan]

When I started turning 30 yrs ago at work , we still used high carbon steel.High speed steel came along and changed everything for the good. I used aluminum oxide wheels with good success.Nothing like a tool right after sharpening With the new steels available, I thought I might take the jump. My question to those in the know is can I use my alum-oxide wheel to sharpen them or do I need a CBN wheel to get the most out of these tools .


Scott, The standard grinding wheel works fine for the newer steels such as the 10V that Doug Thompson uses, no difference really from grinding the carbon and high speed steels. I used the blue Norton 3X wheels with Thompson's tools for years.

That said, I have switched to CBN wheels (from Ken Rizza). Some advantages are the wheel never needs dressing, the wheel never changes diameters, there are fewer sparks, they supposedly run a little cooler (although I'm not convinced), they never get unbalanced, and the wheel can't explode and take part of your face off. Disadvantages are the high cost, and almost never a problem, you can't true the wheel if it is not running true.

I know a lot of turners who have switched to CBN and all of them seem to be glad they did.

JKJ

[John Nordyke]

Aluminum Oxide wheels will sharpen all the steels. However, for a given value of 'sharp off the wheel' it isn't so much the abrasive material or even the grain size that moves you from sharp to REALLY sharp - it is the constancy of the plane at intersection of tool and wheel. Assuming a perfectly steady hand, zero vibration, zero deflection of the tool rest, the most significant culprit in my opinion is runout from the wheel. Aluminum Oxide wheels tend to have more runout than CBN.

[Scott Ticknor]

Thanks for the reply fellas, I`m thinking that if i go the CBN route I will retire my 25 yr old Delta 6 in. grinder and move up to an 8 in grinder, When i bought the Delta it was all a young guy could afford. I like the fact that the CBN wheel stays the same size and runs true. Good to know that for the time being I can still try out some of the newer offerings without a huge initial outlay. For me there is nothing like the hiss of a sharp tool on wood !

[David Gilbert]

Keep your 6" grinder for the occasional lawn mower blade sharpening and other nonessential grinding. The CBN wheels are too expensive to waste on such pedestrian items.

I want to add that according to Dave Schweitzer of D-Way Tools you can sharpen hardened tool steel on CBN wheels. They do a great job on chisels and plane blades as long as they are hardened. Annealed (soft) steels will clog them up.

Cheers,
David

[Ronald Blue]

Aluminum Oxide wheels will sharpen all the steels. However, for a given value of 'sharp off the wheel' it isn't so much the abrasive material or even the grain size that moves you from sharp to REALLY sharp - it is the constancy of the plane at intersection of tool and wheel. Assuming a perfectly steady hand, zero vibration, zero deflection of the tool rest, the most significant culprit in my opinion is runout from the wheel. Aluminum Oxide wheels tend to have more runout than CBN.


You don't dress your Aluminum Oxide wheels? That's grinding wheel 101. Any conventional abrasive wheel has to be dressed or trued for the best results. No conventional wheel is true enough out of the box to work well. You might be lucky enough to have okay results from it but if you want to get the best results it needs trued up. This also needs to be done when the wheel glazes or wears unevenly.

[John Nordyke]

Absolutely you have to dress the wheels, Ron. But my experience has been that even freshly-dressed AO wheels don't run as smoothly/vibration free as CBN on the same grinder.

[Reed Gray]

The metal CBN wheels come spin and bubble balanced. This is why they are vibration free unless your grinder is out of whack. The standard wheels, like wood, can some times be unbalanced no matter how trued up they are.

robo hippy

[John K Jordan]

...The standard wheels, like wood, can some times be unbalanced no matter how trued up they are.
robo hippy

I just mentioned in another thread that I found that to be true with the Norton 3X wheels I used to use. I used the OneWay balancing kit to perfectly balance them.

JKJ