norrin_radd

Hay Mower Blade Challenge!

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I hadn't heard of mower knives being boron alloy yet .... only rotavator blades...so I too engaged in google-fu. Which i wish i didn't haha ... xxxx metallurgy.

  It seems lots of knives,blades and teeth in agriculture are using boron alloys in place of regular carbon due to increased wear resistance. It's essentially medium to what we would consider the lower end of what is considered high carbon steel (0.38-0.54 %C depending on the specific boron alloy) with a small amount (0.0005-0.003%) boron added to increase harden-ability. According to some patents and other info I have found.. They are also marquenched to further increase harden-ability during manufacturing but if I read right this is to get an optimal result and they can still be forged using traditional methods and an oil quench and temper. I mentioned it before in other threads that according to my "research" ...the rotavator/tiller blades are usually either 50B50/50B50H or 6150 ...and from what I have gathered about the mower blades so far is that the boron alternative used in them is 10B38. Hershel USA also admits to using 10B38 instead of 1080 in their sickle sections (those serrated triangular thingys) so I wouldnt doubt it if they also use it in their flail mower knives. I also read that there is a chance of them being made from AISI 9255 if they were manufactured in Europe.

  All this is indicative of the double edged sword that is junk/farm steel .... On one side it's free material that you know will harden well enough. On the other ...you really dont know for sure what the heck it is.  But the way I look at it is that if the alloy was used as a knife for agricultural/industrial purposes, and it can safely be forged and heat treated ..... Then I am going to make knives and sharp things out of it. And I am going to curb my internet alloy delving a bit ....

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I think the spandex blacksmith illusion was first done by Monty Python and his merry minions, if my memory serves me well. Who can ever forget the "I'm a lumberjack and I'm O. K." song.

It is rumored on good authority that it was almost adopted as Canada's new national anthem!

(the old one had one too many "we stand on guard for thee")  plaintive refrains.

Just my two cents on the subject.

SLAG.

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I just changed one of these out today, the are not very hard, I bend them quite often. Today all it took was an old rotted chunk of wood at the edge of the field. I have a large pile saved up for just such a project. Looking forward to seeing others ideas for them.

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Here is the latest K.S.O. I made from a hmb (hay mower blade). Still a little rough but I was happy with it. The one pic shows my cardboard mock up I was trying to go for, inspired by the CRKT minimalist knives, came close. First time I tried a tapered tang too.

I did some tests on this one after heat treating. I dropped it on its tip on concrete from about 5.5'  and it didn't bend, I did feel a little rough spot with my finger nail. I got it shaving sharp and have been cutting all manner of things with it for 3 days, paper, cardboard, whittleing hardwood sticks etc. It seems to be holding its edge well, still shaves. Was a pretty fun project. I really like using the recurve blade.

 

 

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Also I've had it wrong in my head for months thinking these might be similar to 1095 its more like 1065, I just got crossed up. I'm still a noob when it comes to all those numbers, still a fun mystery steel, and the price is right. ;)

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