Atoma Diamond Sharpening Stone - #400
Atoma Diamond sharpening stone from Japanese manufacturer Tsuboman with granulation #400 grit is a standard diamond plate for flattening sharpening whetstones and to repair damaged blades. It removes material very quickly (both from whetstones and when repairing knives), works very well with all types of steel. It is crucial in the knife sharpening process that your whetstones are always flat, as it will preserve the life of your stones and ensure accurate and efficient sharpening. Always splash some water on the diamond stone before sharpening.
Excessive force should not be used when sharpening with Atoma diamond stones as this can remove diamonds from the plate, which, when pressed roughly, can loosen, thus destroying the surface of the plate.
One of the main arguments why diamond sharpening stone works so well is that it is completely flat and does not deform/hollow when used. On the surface of the stone are exclusively monocrystalline diamonds which are more expensive than polycrystalline, but much more durable. They are bonded to the plate by the electrolytic process.
Diamond stones can be compared to sandpaper in structure - both have a thin layer of abrasive surface attached to a non-abrasive base. Of course, the lifespan of the two is not comparable - the diamond will last much longer. Initially, the surface will be extremely rough/sharp, followed by a long period of medium roughness which will eventually wear off. While this diamond stone is sold with a 10mm thick aluminum base (glued to the diamond plate), a replacement #400 grit plate can be purchased separately when the original wears off.
Dimensions (LxWxH): 210 x 75 x 11.5mm (8.3" x 3" x 0.45")
- For stone flattening - secure the whetstone that needs to be flattened with a stone holder. Placing the diamond stone on top of the whetstone, use circular and up-and-down movements to begin flattening process. For better results, draw a grid on the whetstone with a ballpoint pen or a pencil (do not use markers, those can be absorbed into the surface of the stone). When the grid is no longer visible, the stone is flattened. Thoroughly rinse both stones to remove any excess material. Flattening whetstones to up to #5000 grit will get you good results by only using the Atoma diamond stone, while for higher granulations we recommend finishing with the Nagura - dressing stone to get a smoother/finer surface on the whetstone.
- For knife repairs - place the diamond stone on a flat surface and make sure it won't move around (use a stone holder for the most secure position). Proceed with the same movement/sharpening technique as with whetstones to fix a damaged blade (see our Knife Sharpening Guide for details).
Advantages of diamond sharpening stones:
- quickly removes material when repairing or changing the blade's geometry
- quick sanding and straightening
- can be used for sharpening very hard powder steels (ZDP-189, HAP-40, R2)
- it retains its shape and does not deform (become hollow) with use
- lower granulations (#140 and #400 grit) are excellent for flattening whetstones
Disadvantages of diamond sharpening stones:
- for a really fine/smooth edge and for very precise sharpening, whetstones are a much better choice - diamond stones are too rough
- not suitable for making "kasumi (mirror) finish" on the blade
Tip no.1: When flattening stones, one should never forget the edges of the stone. In the process of flattening, we create sharp edges that need to be smoothed out at the end. Sharp edges of the whetstone are fragile and can damage the blade of the knife while sharpening.
Tip no.2: Once done with flattening, rinse the whetstone and diamond plate thoroughly under running water to remove any material residue. For better results, use a (tooth)brush or sponge, but do not try to clean the diamond plate with your fingers, it is not very pleasant (tested and not recommended 😊).
Tip no.3: If you want to reduce the number of stones in your sharpening set, Atoma #400 can also serve as your base stone from which you can then proceed to #1000 grit whetstone and higher granulations. At the same time, you can also use it as flattening stone.
Yesterday I cooked a Chinese meal for a couple of friends: a main mie dish and verious side dishes. Preparing all the vegetables and meat with this Santoku was a joy: effiortless and precise cutting. Probably this inspired me to be as precise in the cooking itself, because we all agreed that it was the best version of this recipe I ever made.
This is the second knife I purchased from SharpEdges. The first one - a Yoshida kiritsuke 135 mm black HAP-40 is also very good. I like the (almost) minimalistic simple but (almost) perfect finish of these Yoshida blades and handle.
All in all I regret that I did not discover your shop earlier. I already have a nice collection of other Japanese knives with different steels and shapes. No need on the short term for replacements or filling some gap. But who knows?
Delivery by DHL Express from Ljubljana to the Netherlands is okay but not perfect. Oh well. Who cares?
Thanks guys for the good service, the European sense of humour and the - especially that - great products.
Well received and everything in great condition, great knife bag and the blade covers fits perfectly... Thanks
Ciao, ho acquistato questo coltello per tagliare la pasta che faccio in casa. Premetto che sono mancino per cui gran parte dei coltelli giapponesi faccio fatica a trovarli. Il coltello è piacevole ma non propriamente da mancini. Un saluto
Very special handle,nice!
I just received my Yoshida Hamono ZDP189 santoku and I am over the moon with it. It was a hefty purchase, but well worth it. I’m currently restoring my knife collection since my previous one was stolen. This is a wonderful addition to my new collection.
Nice wrapped and really safe, amazing knife as a Santoku I had bought and really comfortable to use for whole day prep in the professional kitchen.
I purchased a knife from this website, unfortunately the knife was not of my liking, they provided a return label for me, then Fedex lost the package and it was a mess, lots of calls and emails but sharpedgeshop was always professional and gave me a full refund, they always responded to my emails quick and were very professional.
During the Purchasing process and a year later when I wanted to have something repaired, the service has been outstanding. Prompt responses and working with me to find the right solution.
Beautiful blade and handle. Thanks Sharp Edge!
Will be buying from here again due to the fact that the customer service made me feel like no matter what I'd have everything I needed and be getting my money's worth. They care about your experience and also have brilliant products
Knife was bought as a gift and the receiver loves it. They were responsive when emailed a question and the knife arrived fairly quickly.
It was a pleasure to shop here, so much information and good advice to help you find what you are looking for, pair that with exceptional service and communication and you have a shop who is dedicated and passionate about what they do. Highly rated and thank you
I ordered a knife for a friend with custom engraving and the customer support went above and beyond to help make sure I received the product I asked for. They were quick, friendly, and considerate, and shipped the knife extremely quickly. When a part of the Saya was damaged during delivery I received a replacement (several just in case) the next day!
The knife itself looks great, is nice and sharp, and is exactly what I had hoped to order. Will definitely order again for myself.
I'm really satisfied with the quality of the knife. A great product. And the customer service was great. I have a very small thing to share and it’s not a complaint at all. The knife was a gift and overall the packing is okay. But the knife box was a little bit low quality and i hope that would be okay with lots of customers and if there is an option to buy a little bit higher quality box, it would be very nice. Thank you.
Prompt and reliable team at “Sharp Edge”. I received my item promptly and was well packaged. I had a query about the handle before I purchased this knife. The team at Sharp Edge actually went to the trouble of doing a test and gave me an answer in four days.(I asked them about the suitability of composite handles for sanitising in hot water). All Is good!