Sintered Ruby As A Replacement Material For The Sharpmaker Ceramic Triangles

kreisler said:
failbot failbot Would you say that the general color of your sample in RL looks very much like the color in the digital photo image?
i have chinese rubies which match the color in your jpeg but my Degussit Fine units have a much darker red color (like a cherry red).

maybe your unit isn't Fine but Medium, whaddya think?
Click to expand...
He is clearly from this box, inscription '#214 fine'. But it is quite old, perhaps the technology is improving. Now I will compare with another sample, newer, I recently received from a friend. As far as I remember, medium and fine now differ only in surface treatment, the composition is the same.

So far, the color side by side of the old one is lighter, but here the processing is still F230, after processing F600 it will be possible to judge the color. A coarser sanded surface is always lighter, this is very noticeable on black Arkansas.
 

Attachments

  • IMG_5934.JPG
    IMG_5934.JPG
    147.8 KB · Views: 17
A difference in the darkness of the ruby also has to do with the amount of chromium in the grains themselves. Light pink aluminum oxide grinding points for dremels, grinding wheels, and the like are still technically ruby, just classified differently from the darker "ruby" labeled grit because of the lesser amount of chromium in them.
 
I polished both stones to F600. The color difference is preserved. I sharpened the right side of the knife with one stone and the left side of the knife with another stone - in cutting edge no difference at 10x magnification (I don't have a better loupe).

Yes, it looks like these bars are initially sintered in very large shapes, and then cut into the right pieces, like marble plates are cut for architectural decoration. Hence their ideal shape and price. They have raw ends, they have traces of the form in which they were once baked. There is no difference in texture, but there is a difference in color. So this is really chromium supplements at different times were different. Technologies are improving.

But I only sharpened a fairly soft knife, for sure, when they are used in industry, the difference in wear resistance will be more noticeable due to the different amounts of chromium.
 

Attachments

  • IMG_5958.JPG
    IMG_5958.JPG
    109.1 KB · Views: 7
Typically sintering is done in the finished form, as cutting sintered material is VERY expensive, and sintering large forms requires MUCH heavier equipment. Different sizes of grains are used in the sintering process as using all one size is more difficult to fuse. Some small degree of warping usually occurs during sintering, so they may have done lapping work to the main faces post-sintering, but they almost certainly didn't cut them from larger blocks.
 
I haven't been sharpening on rubies that much lately, as a friend gave me a naniwa super stone and I'm still use with it. And I thought that for those who would like to decide if they need a ruby stone, expensive or cheap, I could send my original one and maybe someone else added some of the Chinese rubies from themselves. That is, a parcel of different ruby stones goes in a circle, like some girls in films. Maybe ~ a month per person to have time to try on different types of steels and knives, and pass it on to the next person? If it takes 2-3 years, it's not a problem. Only 1 condition - to publish here your observations and sharpening results
 
i doht get your XXX movie reference but it sure sounds hawt 💅 🫦🍆🍆🍆🍆🍆💃👠

personally, all i sharpen are shared kitchen knives, and for that I doht use anything but the RRS (retractable ruby sharpener) anymore. let's be honest, once you've mastered sharpening, all you need is 1 stone (e.g. a ruby or the 204M) to produce hair-whittling sharpeness; so i doht bother going through grit progressions anymore.

And #edcknives (typically folding, pocket, clipped)?

i only carry/use my titanium folding utility knife as #realedc, and that knife never needs resharpening (tirant razor v3). i will admit that the utility blade is consistently sharper than what i'd produce with a kitchen knife on an RRS. oh and my most used knife for food prep is the folding paring knife by vinox (an amzn no.1 bestseller) with the serrated blade. never needs resharpening when used as intended (soft foods) because the serrations never touch the wooden cutting board.

I like your passaround idea though!
 
Last edited:
Well, maybe the joke was not clear to everyone, I meant to throw a stone in a circle))

There are some people who are very focused on sharpening, especially kitchen knives. They select their own set of abrasives for each specific knife in order to get the result they need, since each knife is individual. Something like for a specific stainless steel ** hardness XX gives the best result with such and such an abrasive, and for stainless steel *** this abrasive is already worse than Japanese water synthetic stones .. and so on indefinitely))
 
You must log in or register to reply here.
Back
Top