MadHatter Posted December 27, 2011 Share Posted December 27, 2011 Anybody know what kind of steel RotoTiller Tines are made of? A friend gave me one to play with for beginning knifemaking practice, and I'm wondering about how to heat treat it. Is it just high carbon, or some fancier kind of tool steel? chad Quote Link to comment Share on other sites More sharing options...
bigfootnampa Posted December 27, 2011 Share Posted December 27, 2011 I have no direct knowledge but I would expect it to be 1045 or possibly up to 1095. It will not be a complex steel because those are too expensive to use in such applications. Quote Link to comment Share on other sites More sharing options...
macbruce Posted December 27, 2011 Share Posted December 27, 2011 I suspect the steel in rototiller blades is the same as mower blades....I made a knife from a mower blade once that was very tough and hard to sharpen.....I believe boron is added to the alloy to make it tough and abrasion resistant . I used an oil quench and tempered several times but it was still a bugger to sharpen....... John Deere blades" Made from high-carbon, nickel-alloy steel Same steel used for automotive leaf springs. Extremely hard and resistant to wear and breakage. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted December 27, 2011 Share Posted December 27, 2011 cue Curmudgeon: I wouldn't think a steel was "high carbon" till it's closer to the eutectic; I'd consider 60 points a higher medium carbon steel. Quote Link to comment Share on other sites More sharing options...
son_of_bluegrass Posted December 27, 2011 Share Posted December 27, 2011 The tines I've sharpened for our rototiller sparked like a plain medium carbon steel. That doesn't mean that is what you have, just what I have. Treat it like the unknown it is for it could be anything (I've worked with a mower blade that was red short and shattered when quenched in oil and another mower blade that needed water to harden at all.) ron Quote Link to comment Share on other sites More sharing options...
MattBower Posted December 28, 2011 Share Posted December 28, 2011 Nobody can really answer your question. You will have to test and experiment. Down side of using mystery steel. Quote Link to comment Share on other sites More sharing options...
BM454 Posted January 1, 2012 Share Posted January 1, 2012 If you knew what kind of tiller it came from and could reach the company that made it. You may be able to get that info from them. Just a thought. Scott Quote Link to comment Share on other sites More sharing options...
B_edward Posted September 26, 2012 Share Posted September 26, 2012 Earth engaging steel would need to be 0.5 to 0.8 carbon to get the abrasion resistance. Large mower blades are made from low carbon steel heat treated to a bainite structure. This structure is much tougher than tempered martensite thus safer (less likely to shatter and throw schrapnel out the deck) Quote Link to comment Share on other sites More sharing options...
Rich Hale Posted September 26, 2012 Share Posted September 26, 2012 Review for the new! If the mystery steel has enough carbon there are some simple shop things to see if it will harden: Heat to non magnetic and let air cool, clean an area so it has no scale and see if a good fine cut file will cut it. If the file skates and does not cut then it is hard and needs tempered. If it cuts with file then heat to non magnetic and quench in oil, I use atf that I heat to 110f to 120f,,,see again if it gets hard by the same file test. If not then repeat using water as quenchant.If it does not harden it is not usable for a blade, Maybe recycle for another purpose. At any point you get the steel to harden then it will need to be tempered to reduce the hardness which may reduce its likelyhood of breaking in use. I use a toaster oven that is correct heat checked by a thermometor. Try 400f for 45 minutes...longer if the steel is thicker than most normal knife blades. Now youi need to test! using proper prtection see if the blade with one end in vise will bend a little bit and not break. If it breaks it may allow you to slip and lacerate your nearest body part,,Think this through before you try it. If you can bend it maybe 20 degrees and it returns straight and does not break then sharpen it and do alot of test cutting. Staytuned for knife chat as I will test a piece of mystery steel and show more of the process. Quote Link to comment Share on other sites More sharing options...
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