Discordant micron ratings

[Mr.Wizard]

I don’t know how long it has been around but I just found this article: https://support.wickededgeusa.com/portal/en/kb/articles/wicked-edge-grit-micron-progression-chart

The micron ratings therein are very different from those provided previously/elsewhere, e.g. https://support.wickededgeusa.com/portal/en/kb/articles/grit-comparison-table

Can someone explain to me what is going on here?

 

• This topic was modified 3 months, 2 weeks ago by Mr.Wizard.
• This topic was modified 3 months, 2 weeks ago by Mr.Wizard.

[Marc H]

I’m wondering or trying to remember if those previous micron ratings were the visual scratch depth measurements done with high power photography.

Marc
(MarcH's Rack-Its)

[Mr.Wizard]

Marc H wrote:

I’m wondering or trying to remember if those previous micron ratings were the visual scratch depth measurements done with high power photography.

I do not believe so.  The “old” values were posted before the effect-measurement method* was discussed, and the “new” values are described with “This chart is not our suggested sharpening progression, it is simply showing the order of grits from coarsest to finest.”

 

*

wickededge wrote:

Our new system attempts to solve these issues and provide our customers with information that clearly relates one abrasive to the next in an “apples to apples manner”. Here is the approach we’ve taken:

1. Polish to all samples to 0.1 microns
   1. Electro-polish the samples
   2. Continue polishing with 3M diamond lapping films
      1. Alternate with each grit and image at each stage to ensure all previous scratches are removed
2. Apply the grit to be studied to the polished surface
3. Send the samples to LANL to be analysed
   1. LANL will report on:
      1. # of scratches per distance (density)
      2. Scratch profile
         1. Avg width of scratches
         2. Height of ridges
         3. Depth of valleys
      3. RA (roughness average of the surface)
      4. Cross-section profile image of the sample showing scratch width, depth and height

Our thought process is that what matters at the end of the day is what each abrasive does to the knife. Once that is quantified, we should be able to state something like the following: Abrasive X has n effect on the metal. With each grit having a quantified effect, it should be easy to see where each fits within a progression.

1 user thanked author for this post.

Marc H

[tcmeyer]

I’ve been using a micron/mesh chart that was published by Advanced Abrasives about 10 years ago.  It’s always worked for me and seems to match up very close to the chart on the WE grit/micron list taken from the WE support list.

I think it’s important to note that we’re not publishing a set of standards for the industry – just a guideline to use as a frame of reference for WE users.   Which is pretty much was Clay says in his last statement: “Our thought process is that what matters at the end of the day is what each abrasive does to the knife. Once that is quantified, we should be able to state something like the following: Abrasive X has n effect on the metal. With each grit having a quantified effect, it should be easy to see where each fits within a progression.”

2 users thanked author for this post.

000Robert, Marc H

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