Thread: Diamond Spray question

100,000 is about .25 micron, yes?

What micron would 200,000 be?

Is there a chart that can break this down for CrOx and FeOx? Wondering what grit and micron those typically are.

Wanting to know to put everything in order i n my mind.

Rick,

My understanding is that the .50 micron is associated with 30K and the .25 with 60K.

Have fun

Originally Posted by rickboone

Is there a chart that can break this down for CrOx and FeOx? Wondering what grit and micron those typically are.

This will really vary depending on the intended use of the powders. You may need to rely on the individual suppliers to furnish that info.

The CrOx I use is about .50 micron and the CsOx is getting near .15 micron.

Originally Posted by Pauly

The CrOx I use is about .50 micron and the CsOx is getting near .15 micron.

Cesium Oxide (!). Wow!

I think its Cerium not Cesium that people are using for polishing.

Yeah that one. I'm a chef not a chemist

Like I have been saying in other threads, being a chemist and science engineer (German: Diplomingenieur)
you need to understand that there is no such thing as a consistant rating system for grits or sub micron particles.
That is why there are so many different standarts and so many confusions and misunderstandings.
Pardon my french, but even Lynn, a master at sharpening and an eminent authority on this area of expertice, demonstrated the misunderstanding quite well.
He said a particle size of 0.5µm would be associated with a grit rating of 30.000.

What Lynn failed to do is tell us what grit rating system he was referring to!
If he said a sharpening stone with the dominant particle size being ~0.5µm is associated with a Mesh grit rating of 30.000 (according to shaptons Mesh grit rating, that is!),
he would be absolute correct. But what would that help? Not at all, I´m afraid. Because if you ask industrial standard users what Mesh grit rating includes a dominant particle size of 0.5 some would say 60.000, others would say 50.000. And they would all be correct.

Why is that? Because these systems are not absolute and not meant to encourage comparison between different brands or types of abrasives,
but to ensure the quality standards within one manufacturer.

So there is no definite answer to the original question. You will have to ask the manufacturer about the particle size distribution of his product to be 100% sure.
Fortunately stropping on a fine abrasive is no rocket science and even though we can never be absolutely sure what exactly we are stropping on,
if the quality of the product is absolute (that means no huge particles present) it does not really matter if it is 0.5µm, 0.25µm or 0.1µm

Use it and see where it fits into your progression!

Here is a little background information about particle size ratings I wrote a while ago
Grit rating systems in sharpening stones.pdf

On the point about 'all particles in the system are of spherical shape' (from the article linked above), garnets in coticules, diamonds, etc., for example, are definately 'equidimensional' as are probably many synth. hones, whereas abrasives in Jnats are platy (and viva la difference!). Particle size/settling measurement by Stokes' Law does assume 'equivalent spherical diameter', but most modern particle size analyzers use other detection methods than settling velocity. The assumption that all particles are fully dispersed prior to measurement is probably at least as important as anything else in contributing to possible particle size measurement errors.

A gentleman from across the hall put a few graphs together illustrating the various grit classification schemes:
http://badgerandblade.com/vb/showthr...it-Graph/page2

(insert 'Geek Smiley' here...)

Not so long ago I was testing two types of 0.5um diamond powders. One was a round cut and the seccond a short cut.

Compared to the spray I already had, the round cut to me cut like a 0.5 - 0.25um spray and the short cut was somewhere between the 0.5-1um spray i already had although both powders, like I mentioned, were 0.5um.

But, it makes sence that if the diamond particals have no edge to cut its going to give the effect of a smaller, slower cutting partical. If it has sharp edges, it will cut fast but leave more ovious micro scratching.

So, they were both diamond thus its more then just what the partical consists off, its hardness and shape, and then its the consistency of both singularly or combine. The you have the surface that your using it on and so forth.