M42 steel saw blades turned into kitchen knives

That looks good enough to scare the hell out of dinner guests :)
 
me2 said:
That's a helluva band saw. It could be solid then. The best way to tell might be price. Do you have any idea how much the blades cost? Will the blades bend at all before breaking?
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I have no clue on what they cost. And they usually don't break, but when they do it's is mostly where the blade ends are welded together.
 
Thanks for all the complements. I think I will make a meat fork, and a set of matching steak knifes. Maybe a Wood
presentation box to hold the set too. I really enjoy making stuff like this. I also have some d2 that I am making some
more tactical type of blades with. I'll post pics when finished.
 
if it is solid m42 you will know that stuff is supper hard and incredibly wear resistant. try scratching the spine with a knife of known hardness and see which one wins
 
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If it IS a bi-metal blade, that would indicate it's rather critical to get the orientation right when making it into a knife, no?
Hard spine and soft edge would be a shame.

-Daizee
 
Nebulae said:
if it is solid m42 you will know that stuff is supper hard and incredibly wear resistant. try scrating the spine with a knife of known hardness and see which one wins
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I just done this with my esse 4 and the spine of my m42 knife just rolled the edge right off of my Esee. and if I recall,
Esee heat treats their blades to 58 rc. It did not leave any mark what so ever on the spine of the m42.
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Just an update:
I just called the manufacture of the blade and the teeth are welded to the backer blade, however the teeth are actually m71 and rc of 70. And he thinks the backer is made of m42. He is looking into it and promised to call me back.
 
Ok I just spoke with the manufacture and the m71 teeth are welded to a D6a steel that is used for the backer. Now I
don't know anything about "D6a" other then I'm guessing that it is a variation of D6 tool steel. If this assumption is true, then it is still very much suitable for a knife blade.

Metal experts please chime in and shed some light on what I am working with. I don't want to waste my time with this
stuff if it is not worth my time. Thanks.
 
D6a sounds a lot like D6AC steel. D6 and D6AC are very different, and I'd bet on D6AC as the backing. D6 tool steel has almost none of the properties one would want in a backing steel for a band saw blade. D6AC is made by Latrobe, among others, and is a medium carbon, low alloy, high strength steel with good ductility (stretch) and toughness.
 
me2 said:
D6a sounds a lot like D6AC steel. D6 and D6AC are very different, and I'd bet on D6AC as the backing. D6 tool steel has almost none of the properties one would want in a backing steel for a band saw blade. D6AC is made by Latrobe, among others, and is a medium carbon, low alloy, high strength steel with good ductility (stretch) and toughness.
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And what do you think about using it as knife blade steel?
 
"D6AC is a low alloy vacuum melted steel containing several other elements and with a carbon content of 0.42 to 0.48%. The hardenability of this alloy is better than that of AISI 4340 and D6AC can be heat treated to strengths ranging from 180 to 260 ksi."

Bummer. Great looking knife nonetheless.
 
It would make a knife blade with toughness difficult to fathom if you're used to normal cutlery steel. For a carving knife, it should work fine. It's not like you're cutting used carpet or something like that. It will turn colors if you use it on meat. My carbon steel knives turn a nice shade of blue.
 
me2 said:
It would make a knife blade with toughness difficult to fathom if you're used to normal cutlery steel. For a carving knife, it should work fine. It's not like you're cutting used carpet or something like that. It will turn colors if you use it on meat. My carbon steel knives turn a nice shade of blue.
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Really? 0.42-0.48 C would make it hypoeutectoid. What do you get if you harden such a steel?

edit further info here http://www.bladeforums.com/forums/showthread.php/673173-Working-the-three-steel-types.
 
Lol, I have to admit, that I am kind of overwhelmed with some of the technical terms, and metal terminology.

From what I think I am getting from what I have read the metal is D6AC, and will get fairly hard, be fairly flexible
without fracturing, and that it is useless as a knife blade. I guess I don't underestand, I would think that for a kitchen
Knife That would be fairly good. Hard enough to take and hold a "Descent" edge, and flex for kitchen type cutting.

Not trying to insult anyone, I just don't know what to think. Obviously, it's not the ideal steel for this pourpose, but is it
An ok steel to use for the kitchen scene?
 
Billyboyr6, if you would like a brief explanation of any terms, let us know. I tend to write as though everyone is familiar with the terms, which is a bad assumption on my part. Hypoeutectoid steels are steels with a carbon content less than about 0.8%. A few of the steels used that qualify are 5160 (popular with custom makers for chopping knives), 420HC (Buck), 1055 (Cold Steel machetes and GI tanto), 12C27 (popular Swedish made stainless steel), 13C26 (slightly higher carbon version of 12C27, same manufacturer), AEB-L (American made version of 13C26), and others. The last 2 are razor blade steels, and I've had very good results with 12C27 and 420HC. Cold Steels machetes of 1055 will cut two 2x4's and still shave my arm, and likely are about the same hardness as your D6AC. The maximum hardness of hypoeutectoid steels is lower than other steels with more carbon, and they have much lower wear resistance, but still have their place for us knife knuts.

I'll clarify a little bit what I mean by unfathomable toughness. This steel will be extremely tough, especially relative to some of the more popular cutlery steels. If you bounce a machete or such off a rock, and it's made of a steel like this, there's practically no chance it will chip at the edge or shatter out right. There's a good chance it will mash/dent pretty good, but you can't get everything in one steel, and geometry has a huge influence on this kind of damage. Traits like this are the reason hypoeutectoid steels are used in the first place.

As a kitchen knife intended for cutting meat (carving knife) I'd think it would work fine. Just give it a good sharp edge, and don't hit any bones too hard. As a broad generalization, if the steel is in it's working range of 250,000 to 280,000 psi, you'll get a hardness in the range of 53 to 56 HRc. This can be found on google with a search for hardness conversion charts. Hardness in this range is relatively low, and you can expect some definate edge rolling if you use it in a ceramic plate/cutting board. However, many kitchen knives are made in this range, and serve for years. Just don't cut anything frozen or try to hack through bones. Aim for a bevel angle of 20 to 25 degrees. If this proves satisfactory, lower it little by little until you feel the edge is too weak. Food is generally very soft, and the cutting board, washing, and storage in loose silverware drawers will do more to dull a kitchen knife than cutting meat, vegetables, plastic wrappers, etc. In short, you have a fine carving knife, and I wouldn't worry about the steel not performing properly, you just may have to sharpen it a little more often. I've seen video of a guy prepare a chicken dinner with a sharpened can lid. As an experiment, get some steel from Lowes or Home Depot and grind a blade from that, then see how it works in the kitchen. For meat and such, it will cut fine, just not as easily or as long as the thinner, harder blades. The strength/hardness just isn't there to hold a razor sharp edge on a 10 degree per side bevel. Past a certain point, weaker steel gets too thin and will just fold/deform. Anyway, its an interesting experiment.


PS: for those familiar with the term Charpy Impact Test, here is another example of how tough steels like this are. The Charpy test uses a large hammer with a pointed wedge on it to break a small (~0.5" x 0.5" x 1.5") bar of steel. A gauge records the the amount of energy in the hammer at the begining of the swing and at the end. The missing energy went into breaking the sample. What may not be commonly known is that cutlery steels typically use a smooth rectangular bar for this test. Steels like D6AC will use the same test specimen size, but will use a bar with a large notch cut into it. These steels are so tough that without the notch, they stand a chance of just not breaking, and bringing the hammer to a standstill. The maximum capacity of the machine will determine if that happens or not. The one I used to work with had a 300 foot-pound capacity (same impact as raising 300 pounds one foot then dropping it). We had a couple of steel samples stop the hammer and max out the machine, at 20 below zero. These were structural steels and I know of no cutlery steel that will do that.

PPS: if you can't tell already, I like blades with high toughness. I like blades with very high hardness too, just choose the right property for the task. Holy crap I'm long winded tonight.
 
Billyboyr6 said:
Obviously, it's not the ideal steel for this pourpose, but is it
An ok steel to use for the kitchen scene?
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I wouldn't bother with it, myself. It sounds like false economy to me... sure it's free but there's usually a reason for that. It will "work" I guess, but there are dozens of alloys that would be much better. Blades made from O1 and CPM-154 (for example) perform extremely well, and would cost $5 - $15 max for a blade that size.
 
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