Grit size chart and sharpening stones

considerations

bill tindall, E. TN

>You will be able to find a table that normalized everything to micron particle size but that is not the whole story. How deep a groove that particle makes in use will also depend on its shape and hardness as well as the hardness of the metal abraded. Hence, a true comparison would have to be obtained empirically and I doubt anyone has spent the labor to do that for plane iron steels.

Re: Grit size chart and sharpening stones *LINK*

Derek Cohen (in Perth, Australia)

>Joe

Link below.

Regards from Perth

Derek


Relative grit sizes of belts, stones and hones

Re: Grit size chart and sharpening stones

Warren in Lancaster, PA

>As Bill mentioned earlier, the various sharpening media are different enough to make comparisons difficult. To give an example of the difficulty I will mention two stones that I havs used regularly for years: the soft Arkansas and the King 800 waterstone. Every chart I have seen in the last 25 years lists the soft Arkansas as the coarser stone of the two. Yet, in practice, the soft Arkansas is so much finer that it would be foolish to go from the 800 stone to the soft Arkansas without an intermediate stone.

Understood. Thank you.

Joe in a Cleveland suburb

>

Re: Considerations

Tom Colligan

>Bill, your point is well taken.

But at a more basic level I and others at our level :) would just like to know, for example, how does an 8000 Shapton stone compare to 2000 SiC paper sold in the AutoZone type stores. Can you hazard an opinion here? Tia, Tom

not without a microscope

bill tindall, E. TN

>What is going on becomes hard to judge as the abrasive makes ever smaller scratches. As an example, a soft abrasive may put a mirror finish on an edge but upon microscopic investigation it will be revealed that this abrasive is just polishing the hills and valleys from the prvious coarser grit. The egde limiting hills and valleys are still there, they just look more shiny, which could be interpreted as a highly refined edge when it is not. Diamond charged on cast iron leaves a dull surface even at 1 micron, which could be incorrectly interpreted as a less refined edge. The diamond cuts vee's that trap grinding gunge rendering a dull luster but a sharp edge. To quote another example from Steve Elliot's work, water stones sharpen carbon steels to whatever refinement one wishes. But the aluminium oxide in these stones will not cut through vanadium carbide in some tool steels. Silicon carbide papers presents a particular challenge. This abrasive curshes in use to yield a finer abrasive particle.

To be done correctly someone would have to sharpen some defined steel with various abrasives and then test sharpness by some reliable means or perhaps evaluate results by microscopy. The conclusions would be valid only for that, or similar steels.