Diamond Machining Technology (DMT) Dia-Sharp Diamond Sharpening Stone Credit Card, Extra Fine, Fine & Coarse, 3 Pack

First of all Excellent Product. They are truly credit card sized.Product Review.How to Use: They are the size of a creditcard, and on the back side of the plate is a sticker that tells you the stones information.Blue says: D3C: Coarse, 45 micron (325 mesh).Red Says: D3F: Fine, 25 micron (600 mesh)Green Says: D3E: Extra Fine, 9 micron (1200 mesh)Under that is the DMT logo with their phone number and website address. THe sticker is clear with the letters in the color related to the identification of the stone mesh.When you hold the sharpening stone plates you can feel the weight to them and if you lightly run your fingers over the sharping side of the stone you can feel the coarseness of the stones. You can also see the diamonds shining on th coarser stones the Blue and Red, as where the green coded plate the extra fine it looks like a piece of polished metal.BREAK IN PROCESS:To break in your stones use a cheap knife if you want I did. you may see little discoloration spots on the stones and trust me, it does nothing to the stone. They still sharpen your tool. It does not take alot of pressure to get these diamonds to cut. I use the amout of pressure on my stones as you would just resting your hand down on a counter relaxed. People saying they when they sharpen their tools or knifes with these stones and the diamonds are coming off, that is because they are pushing too hard. Rarely would it be a product defect.SHARPENING PROCESS:They say you do not need to use water or oil. I get my stones lightly wet with some water before sharpening. The reason is the water on the stones else collect the loose shavings so you don't have to worry about them in the cleaning process. To hand sharpen a knife for example, you can hold the stones in your hand and while *PAYING ATTENTION* sharpen your knife quite easy with out cutting your self. The way I hold the stones is the following. Follow these steps. (wish i could upload photos) Palm up hand open take your ring middle and index finder and put them together, if you have small hands use ur pinky too. Now your thumb you can brace the corner of the stone if you want but you wont need to because you will not need to use alot of pressure, hence the stone wont slide around on your hand. The weight of the stone will be enough to rest in your hand or on your fingers with out it moving around. Now I don't wear gloves while sharpening knifes and I know I should for stones this size and because they are being help in my hand. Yes I can easily cut my self, but I like to feel the stone in my had and I have the experience. For this review I am going to advice you to wear some sore of protective leather gloves, just for my own peace of mind so if you loose concentration or slip you don't cut your self. It requires little pressure and just go slow. one pass should take 2-4 seconds. Do not go fast go slow and steady. Start with the blue stone, then the red stone then the green stone. For touch ups on knifes green or red may be enough. For some good re beveling blue is needed or if it is really dull. If you have to do allot of re beveling and deep shaving these are not the right stones for you. Look into the DMT Dia Sharp 8" Stones. They come in all 6 grits. These are for on the go or even at home simple and quick sharpening. For any big projects like a busted tip knife, super bull knife you need to look into the DMT Dia folds and or the DIA sharp stones. I do say the 8" DIA sharp stones because they are the only size in all 6 Grits. from Extra Extra Coarse to Extra Extra Fine.CLEANING:To clean your stones simply run them under water and get a soft tooth brush from the store and lightly scrub them. the water and the tooth brush is enough to get the metal filings out. Do not use a SOS pad or a metal wire brush Why you ask? 1. these stones will cut the metal from the brush and just embed more metal into them. 2. You can scrape off the diamonds if your pressing really hard. All you need i a tooth brush and some running water. Now for some harder cleaning you can use some commet or dish soap. If you do not press super hard on these stones and use light pressure and rinse/wash them after each tool you clean you wont have shaving deeply embedded in them. I will sharpen 1-3 knifes before cleaning.STORAGE:For storing these stones, please make sure the are 100% dry. After cleaning them as mentioned above you need to dry them. do not rub them dry with a paper towel or a towel. Simply pad them dry. If you want use a hair dryer after padding most of the water off or a air compressor and lightly blow off any extra moisture. Place them back in the corresponding sleeves. I put my stones with the cutting side facing to the colored side of the holder. The reason is the transparent side is a bit short and you have a chance of your stones being slightly exposed and I would rather have the back of the plate corner exposed than the cutting front side exposed.Finally I would recommend these stones to anyone who wants to keep and maintain their tools properly. They are the right size for travel. If you are a prepper they are truly pocket sized and the size of a credit card. It is worth to but this combo pack and not the individuals. You truly use all 3 stones. If you have the bigger bench stones you should still get these. They are small enough and would be perfect for a hunting/fishing tackle box. They will NOT sharpen Serrations. For that you need the "Diafold Serrated Knife Sharpener". I would recommend that you buy all three variations of those as well. I wish these came in Extra coarse and Extra Extra fine. Maybe in the future they will come out with them in those styles. With enough pressure from consumers they will have the incentive to make them. If there is a demand there will be a supply as the person from DMT told me on the phone. If you are ike me and want the 12inch Magna Stones or the "Diafold Serrated Knife Sharpener" in all 6 variations of mesh please call DMT and tell them. They need to know they there is a demand for them before they will make them.I hope this review was helpful if so please click like and comment if you wish. IF it was not helpful please leave me a comment telling me what was not helpful and what information was lacking and I will be more than happy to add the information to the review.Have A Wonderful Day!

Okay, so I feel like I may need to justify the fact that I do have a real need to sharpen things on the go on a fairly regular basis. I started a small sharpening and tool refurbishing service with my retired father out of his shop on the weekends after I'm done with my day job. I'm saying all of that to hopefully explain away the sharpening geekdom I'm about to lay down. We'll see how it goes... I do also have a rather modest (okay...massive) personal collection of items (knives, swords, axes, shovels etc...) that require semi-frequent sharpening. So, the necessity of the act of sharpening things aside, I do also sharpen things for fun. It's my way of meditating...So between the amateur and professional experience, I think I've tried nearly every different sharpening device or method known to man. Giant Tormek machines; wet and dry grinding wheels; tri-hones by the dozen; oilstones of every size, grade and shape; natural and synthetic Japanese waterstones; corundum paper wrapped over mirror glass; quartz belts; leather stropping belts; a solid hand-cranked quartz grinding wheel that belonged to my Great-Grandfather, viking whetstones, the top edge of a car window glass...everything. And the only ones that have stood the test of time and effectiveness are the diamond plates. They don't dish, they don't wear out (only seeming to get better/smoother with age) and they can even be used to level/flatten out other worn out/dished stones. A tool that does the job better than anything else and can actually fix other tools? What else can you say that about?! And beyond the hype, I can vouch that the DMT's are the best of the bunch. I've tried the alternative brands and the DMT bonding process is just plain stronger than the competition - so the grit lasts longer. From a connoisseur's POV, the mono-crystalline diamonds they use actually do seem to make a positive difference when you're trying to get a tough material to cut. The feedback is better too.Now while I do appreciate that I scored this set at a huge discount over purchasing the cards separately, I'd also have to say that carrying all three of them together in your wallet is a patently ludicrous proposition. The weight of the cards alone is enough to turn your wallet into an incredibly ineffective (and expensive) shot-put. Combine that with the fact that the Coarse (Blue) plate is only really useful for serious stock removal or possibly re-profiling, (something I usually only tackle on a full bench plate) and the near-uselessness of the Extra-Fine (Green) plate for anything but stropping or lapping (caused by the low grit and super-wide (9 micron) mesh, and you're left with only a 1/3 win. Now, because of my hobby/business, I'll probably be keeping the Coarse grit card close at hand specifically for the time consuming process of sharpening my scandi knives or my axes. Otherwise though, the Extra-Fine card could easily be replaced by a scrap of thin and inexpensive 3M 9 micron (notice it's the same mesh as the SF card) lapping film as an equally effective way to polish an edge or knock loose a burr. Seriously, get some of the film in bulk, lay it on something flat and try it in combo with the Fine grit card. You're nearly guaranteed to come out with an edge that will make the hair on your arm preemptively leap to its death in sheer terror. The back of these cards are even smooth... So you can trace around the card, cut-out a scrap of the film, glue it to the back of the Fine card with a bit of epoxy and come out with a 2-in-1 sharpening dynamo that actually WILL fit in your wallet...without breaking it.Update: The break in time for the Extra-Fine plate apparently took much longer than the others of the set. Needless to say, its managed to suddently become my favorite of the bunch for polishing edges, adding micro-bevels and even stropping/sharpening my diposable razor blades (by running them ever-so-lightly backwards on the EF plate covered with a thin film of honing oil). It takes them back to factory-sharp in seconds. So needless to say, by the money savings alone, that's the the coolest thing since sliced bread!Hope that helps,Thanks again for your time.

These things are great. They'll leave your router bits or, whatever you're sharpening, razor sharp. I test how much hair comes off the top of my hand in one pass to determine how sharp my blades are. I can literally shave with my router bits. I took off all the hair in one pass after I sharpened my router bits. The only complaint I have is that, I've used these for years in the past, and they have a tenancy to have the diamond grit come off after awhile. Although, it does take quite awhile to do so, it does happen. This is due to the adhesive failing after excessive, prolonged use.