Testing cutoff wheels: General Industry Coverage

Dear Doc: I manufacture cutoff wheels and would like to implement some sort of testing program to evaluate them. Can I do this inexpensively? I’m not looking for anything fancy, just a quick method to determine wheel performance.

The Doc Replies: The minimum you need to measure is grinding power and wheel wear. Connect a genuine power meter—not an ammeter—to the grinding wheel motor and measure power during grinding. Grind several test specimens and measure wheel diameter before and after. Calculate the wheel-wear factor (1/G-ratio) by dividing the volume of wheel lost by the volume of material ground.

Courtesy of J. Badger

When testing cutoff wheels, you’re looking for “outliers,” wheels that fall below the curve. These are wheels that, for a given grinding power, wear less.

In a perfect world, you’d have wheels that generate little power (and heat) and wear little. In the real world, “harder” wheels wear less but generate more heat, whereas “softer” wheels generate less power but wear more, meaning they’re freer cutting. This is shown by the curve in the figure.