Gergely Posted November 19, 2014 Share Posted November 19, 2014 Hey All, I just want to share this story that apparently no "civil" can appriciate... :) In the late spring I found some 20 mm square bar in the local scrapyard. I thought it was mild steel and took all the 3,5 m/11'. Payed 3$ for it. Last week I was asked to help out a coworker with a short piece of steel. So I took the grinder and chopped a short length of the above mentioned MS stock. I was pretty shocked to see sparks which differed from what they supposed to be. Orange or almost faint red straight sparks with little bangs in the very end of their route. No burst at all. First I thought it could be cast iron but 20 mm square rod is not what cast iron is used for. Then I realized I've already seen these kinds of sparks when grinding a cold cut made of a core drill. Just for fun I put it in the forge see what will happen. It was quite hard to forge, but still manageable. I shaped a cold cut with very dull blade. After it cooled down I ran a coarse file on it - it bit good, not too good but still... Then I heated the business end to orange and quenched it to oil. It hardened to glass hard. Without any edge on the tool I managed to cut pieces from a flat steel surface. I left it as it was. Some days later I continued forming it into a useable cold cut. With a 2 mm thick edge I quenched it to oil, and tempered it to blue. Cold grinded it sharp, and it works like a light sabre. Heavy testing is still on, but it cuts through 10 mm dia MS stock quickly and carves slices from flat stock. And I have 3 meters / 10 feet of that stuff!! Boy, I'm going to make some cutting devices! Any suggestions on useful but not so well known shapes of cutting tools? I did some reading to find out what material it can be. It seems that these kind of sparks occur when grinding high speed steel or steel with high chromium and/or wolfram (tungsten). Does anybody know about the forging abilities of HSS steels? I only heared they forge not easily. Here are some pictures of the cold cut. Thank you for reading this, any comments are welcome! Bests to All of you! Gergely Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted November 19, 2014 Share Posted November 19, 2014 I like a chisel with a broad rocker edge---makes it easier to run a line down a piece when you can start the next bit by placing the end in the last bit and then rocking the chisel over for the new portion. Don't forget an ornate center punch for laying out designs---pineapple twist handle perhaps? A set of short chisels for use with the treadle hammer or flypress, a set of long ones for hand use over hot steel. Quote Link to comment Share on other sites More sharing options...
SJS Posted November 20, 2014 Share Posted November 20, 2014 I use some curved chisels, forge the chisel shape, then sink into a bottom swage... I would make the struck end very broad and just slightly rounded, and get a couple copper or brass mallets for striking these tools. That is the one drawback to using fancy steels for struck tools, it is flat out just safer to use a soft hammer. You don't dent or scar your favorite forging hammer, and the struck tool is less likely to spall and throw chunks into your face or the crowd... I use a lot of S7 and they cut like crazy and last forever but since it air hardens the struck end is hard too... Your milage may vary since this is likely a tungsten alloy and very hot hard... Quote Link to comment Share on other sites More sharing options...
Gergely Posted November 20, 2014 Author Share Posted November 20, 2014 Thank you, Thomas and Shane, for the suggestions. The broad edge really makes sense. On the list it goes! The ornate center punch is a good idea, too. Although I may want to use some other material, because this one is too hard to be ornated. :) Shane: Are you talking about curved blade chisel used on steel? That is something I really haven't heared of earlier. Thanks! I also found these by googling: Any suggestions come handy. So keep 'em coming :) One more question: If the material is very hard and hopefully tough is it worth to grind the cutting edge to a smaller angle as the usual 60 degrees? Bests Gergely Quote Link to comment Share on other sites More sharing options...
SJS Posted November 20, 2014 Share Posted November 20, 2014 Yes I used curved gouges on steel all the time. I use them for profiling shapes like dogs heads, and deeply scalloped leaves. As far as how sharp is too sharp with this particular steel, try making a thin bladed hot slitting chisel and see how it holds up under use. This would also seem to make an ideal material for slot punches and round punches, try it and see... Quote Link to comment Share on other sites More sharing options...
Gergely Posted November 20, 2014 Author Share Posted November 20, 2014 Wow, thanks a lot! G Quote Link to comment Share on other sites More sharing options...
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