DanielC Posted December 29, 2019 Share Posted December 29, 2019 Working on a big batch of sanmai. About 11 pounds worth of sanmai actually. Most of it is straight low carbon jacket steel sanmai, and a small portion was 410 SS jacket sanmai. All of the billets contain a flavor of German tungsten carbon steels that resemble what's available to Japan from Hitachi. I've had problems with SS sanmai in the past, but was able to pull through this time. Forged quite thin as well. All 3 knives have a spine thickness above the heel .105" thick or thinner (the small blade is like .089" above heel at spine. Anyone who has forged SS sanmai, knows forging it thin is quite dangerous as the SS likes to be HOT or the billet wants to break apart. Heat treated this batch along with some test swatches to check my HT of these difficult steels, with great success. Both the SS and core steel display silky tiny grain, even zoomed in. Core steels are 1.2519, 1.2442, and 26C3 ( not a tungsten steel) More to come. Quote Link to comment Share on other sites More sharing options...
DanielC Posted December 29, 2019 Author Share Posted December 29, 2019 60 grit off the belt inspection. Core centered on both sides, edge is at .010-.005ish. Taking to disc sander to refine and move up in grit and maintain consistent surface. Then to stones. Will grind what is known as a hamaguri grind. Quote Link to comment Share on other sites More sharing options...
Daswulf Posted December 30, 2019 Share Posted December 30, 2019 Nice. Look forward to watching your progress on these. Quote Link to comment Share on other sites More sharing options...
Jasent Posted December 30, 2019 Share Posted December 30, 2019 Tagging along Quote Link to comment Share on other sites More sharing options...
Latticino Posted December 30, 2019 Share Posted December 30, 2019 These look fantastic so far. I attended a recent hammer-in where a demonstrator (sorry, have forgotten the gentleman's name) very quickly nocked out a SS Sanmai billet in well under a minute, not counting heating up, using a large rolling mill. Of course he had previously cleaned up the stock and done a full perimeter weld, but it was still a pretty remarkable feat. Two passes though the mill and the billet was completely welded and forged down to usable thickness. It happened so fast I could hardly even take notes, much less blink... Quote Link to comment Share on other sites More sharing options...
DanielC Posted December 30, 2019 Author Share Posted December 30, 2019 Yea these took a bit more time than that. I am in the process of building a rolling mill, but until then, I just draw it carefully out under the power hammer. Quote Link to comment Share on other sites More sharing options...
Latticino Posted December 30, 2019 Share Posted December 30, 2019 He was using an old industrial grade rolling mill, and processing a blank that was about the size that could be used for one or two kitchen knives. The rolling mill was about the size of a Fiat 500. I don't think a homebuilt one could be quite that effective. He just zipped it through the mill twice and it was done. Anyone who had done SanMai by had was just left picking their jaws up off the ground. Quote Link to comment Share on other sites More sharing options...
DanielC Posted December 30, 2019 Author Share Posted December 30, 2019 No, not at all I've had my sights on a few 15hp rolling mills, but until I get my big, big hammer set up, it isnt in the cards. A modified mcdonald rolling mill will be fine for knife size billets after I hammer them down a bit. Quote Link to comment Share on other sites More sharing options...
DanielC Posted January 2, 2020 Author Share Posted January 2, 2020 Got the first of 3 almost finished. Now for the handle and saya. The geometry of the blade is called hamaguri. Ready to sharpen now. Quote Link to comment Share on other sites More sharing options...
JHCC Posted January 2, 2020 Share Posted January 2, 2020 That is gorgeous. Quote Link to comment Share on other sites More sharing options...
DanielC Posted January 4, 2020 Author Share Posted January 4, 2020 Quote Link to comment Share on other sites More sharing options...
DanielC Posted January 7, 2020 Author Share Posted January 7, 2020 Here is another one with a core steelcsimilar to Aogami 1 called 1.2442. This knife is a little different in that the wide bevel is coherent to the forged surface, and will be stone polished. These pictures show the multi-faceted bevel that is called Hamaguri in Japan. I take the edge to .001-.002" on a disc to 220, and then take it into my home where I will begin my process of stone polish. By the time I'm moving into natural stones from synthetics, the edge will be 0" and rather forming a burr. Usually I sharpen a secondary bevel in but ive had some requests not to. This would be reserved for pretty much only the most serious stone polishers to be practical, as the act of polishing the entire wide bevel is also sharpening, much like sharpening single bevel knives from Japan, except you are forming a burr twice. Quote Link to comment Share on other sites More sharing options...
JHCC Posted January 7, 2020 Share Posted January 7, 2020 Gorgeous, as always. Interesting sander in that last photo. Is that a horizontally spinning disc mounted directly on the motor shaft? Have you done a thread about that anywhere? Quote Link to comment Share on other sites More sharing options...
pnut Posted January 7, 2020 Share Posted January 7, 2020 Impressive as always. You never fail to show great work. It looks like a wheel my friend does lapidary work on. Pnut Quote Link to comment Share on other sites More sharing options...
Anachronist58 Posted January 7, 2020 Share Posted January 7, 2020 Beautiful Three Flat Things. I too, am interested in your sander. Robert Taylor Quote Link to comment Share on other sites More sharing options...
SLAG Posted January 7, 2020 Share Posted January 7, 2020 Folks, Similar flat grinding, sharpening horizontal wheel systems are available for sale at, 1) Woodcraft stores, and, 2) Lee Valley Tools. I am certain that other vendors, also, sell similar sharpening, (& grinding), tools too. SLAG. Quote Link to comment Share on other sites More sharing options...
DanielC Posted January 7, 2020 Author Share Posted January 7, 2020 This is indeed a horizontal disc grinder. I made this one actually, modelled after the ine KMG makes. 1hp motor with a KBAC VFD for total speed control. I basically plasma cut out of .250" 1018 plate a motor mount. Install motor, vfd and disc. I spent around half the cost of the KMG model. Quote Link to comment Share on other sites More sharing options...
JHCC Posted January 7, 2020 Share Posted January 7, 2020 Cool; thanks. Quote Link to comment Share on other sites More sharing options...
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