ANSI or JIS or FEPA?

[aquataur]

I better start a new thread or nobody will see this.

cbwx34 recently wrote to me over a different subject quoted in the following book:

(...)"Razor Edge Book of Sharpening" (which you can now get for free HERE)(...)

John Juranich writes in this book on p.56 that they use two "hones" as they call them, a "fast cutting" abrasive which he calls "fine" in the order of #100 and a "finishing" abrasive in the order of #400 to #600.

Now sharpening with two stones is basically coincident with today´s common agreements, but in the lights of today´s ever higher grit stones into the #10.000´s I wonder what grit gauging standard he is referring to; because #100 appears a pretty rough brick and #600 not very fine.

The reason I ask is because it interests me what he has to say on what he calls the "relief" (tapering the knife behind the edge, as discussed here). He does the relief with the coarse stone without further refinement, and only does the edge with the fine stone.
[he also does not mention about removing the pesky burr...]

I would guess (from the optics) that the book was printed in the 70ies. What standard may he refer to?
I doubt that back then Japanese waterstone sharpening was en vogue the way it is today.

Maybe somebody knows.
Thanks
-Helmut

[RickKrung]

I would not worry much about it.  It does appear to be older info and it is curious there is no publication information, as usually appears shortly after the title page.  May be sort of like the deluge of info on the internet these days, one cannot always take everything on face value. 

It may be safe to assume his grits are similar to what we commonly refer to.  Likely he used whatever was in common use at the time, in his location.  1970s?  USA? 

If you want to compare grit rating scales, I would look for info that relates whatever rating system shows what the grit sizes are in microns (µ) as a standard for comparison. Here is something that discusses all the ones you list and more, but very little reference to micron sizes.  I didn't find it very useful.  Here is a chart comparing the different rating systems, but that still doesn't help with know what your book used. 

Try his method yourself and judge for yourself.  Or, just go with whatever you have found works and/or simply take advantage of the wider array of grits and wheels available to suit your needs and desires. 

Rick

[3D Anvil]

Hard to say from the quote.  As a rule, the different rating systems are fairly close at the coarse end, but differ considerably at the fine end.  For example, a FEPA-F 600 grit is equivalent to FEPA-J of around 1,350.

https://www.gritomatic.com/pages/grit-chart