Mr.Wizard
@mr-wizard
active 8 months, 3 weeks agoForum Replies Created
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The chart has been updated to revision 15. The directory link in the original post has been broken. Here it is again:
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.”
*
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:
- Polish to all samples to 0.1 microns
- Electro-polish the samples
- Continue polishing with 3M diamond lapping films
- Alternate with each grit and image at each stage to ensure all previous scratches are removed
- Apply the grit to be studied to the polished surface
- Send the samples to LANL to be analysed
- LANL will report on:
- # of scratches per distance (density)
- Scratch profile
- Avg width of scratches
- Height of ridges
- Depth of valleys
- RA (roughness average of the surface)
- Cross-section profile image of the sample showing scratch width, depth and height
- LANL will report on:
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.
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This is my latest “concept project”. I was curious if this type of diamond stones were any good.
That looks expensive. You must be quite a perfectionist to not just use his 4″ stones. https://www.cgsw.us/1×4%20Resin%20Bond%20Diamond%20Stones.html
If the shears will be used for slide cutting, whether fabric or hair, you may want a polished edge.
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To avoid a possible misunderstanding I did not perform any testing or measurement myself. I am merely using the values that Clay provided. The old/original 1500 was previously listed as 5µ in the Wicked Edge grit table. Thank you for your testing however!
Marc, that’s quite a collection.
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- Polish to all samples to 0.1 microns
