Mower blade for knife

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porthos

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as the title says: would a junk mower blade make a decent blade. probably has been adressed before; but, i don't go on the knife section much
 
Depends what you want but I believe mower blades are tougher than they are hard. So it would be an okay machete perhaps but won’t hold a keen edge. Just what I’ve gathered poking around the web, so of dubious reliability, but it makes sense.
 
Agreed, it's the use that decides what would make a decent blade. For generations people have made knives out of mower blades, saws, files, leaf springs, anything made of steel with enough carbon (1-2%) to allow a good heat treat. But are you making a kitchen knife, or a skinner, or a folder, or a utility knife? The knife a gardener or lettuce picker wears on their hip might not be what you have in mind. Tough steels make great working blades, but to shave your face or scrape a hide might require something quite a bit harder. High tensile strength is ultimately what to look for.

VG10 is great stuff for multipurpose knives. D2 is incredible for mirror-finish razor edges, but it chips easily. Sandvik's S35VN is what's in my pocket today, and the stuff is amazing- hard, chip-resistant, but expensive. It costs less than crucible steels, though! There are some maraging steels out there that are good, like N690Co and a bunch of Chinese blade alloys, but I don't think they are as nice as the HSS steels that cost less, or the aforementioned Japanese VG10, which holds a place in my heart for the most well-rounded and affordable blade steels.
 
I figured old mower blades would be good steel, so I threw one in the forge, got it up to a good quenching temperature, and dunked it in oil.

Nope. Not hard at all.

I tried again, this time using water.

Nope. Not hard at all.

I took it to a higher temperature, getting it almost white hot.

Not hard in oil, not hard in water.

I took it to white hot. All I did was ruin the steel.

I tried taking it to a lower quenching temperature.

Not hard in oil, not hard in water.

Unless you know something I don't, the average mower blade is low carbon steel, and you can't make a decent knife out of it, unless your idea of a decent knife is something that dulls as soon at it cuts a few sheets of paper.
 
Nice testing. Did you try a spark test? I heard that they are intentionally soft. High grade rebar and sucker rod will snap after a hard quench, and they are just barely medium carbon.
 
Hi,
Mower Blades are no good as mentioned.

Old Nicholson "Black Diamond" files are 1095 and make great knives.

Old auto leaf springs are 5160 steel and make great knives if heat treated correctly.

I still have knife making steel, from a 1939 Studebaker truck, that makes great knives, beautiful steel!

Just sayin, plenty of easy to find steel ,WAY better than mower blades to forge with!
 
dewbane said:
I figured old mower blades would be good steel, so I threw one in the forge, got it up to a good quenching temperature, and dunked it in oil.

Nope. Not hard at all.

I tried again, this time using water.

Nope. Not hard at all.

I took it to a higher temperature, getting it almost white hot.

Not hard in oil, not hard in water.

I took it to white hot. All I did was ruin the steel.

I tried taking it to a lower quenching temperature.

Not hard in oil, not hard in water.

Unless you know something I don't, the average mower blade is low carbon steel, and you can't make a decent knife out of it, unless your idea of a decent knife is something that dulls as soon at it cuts a few sheets of paper.
Click to expand...
grass dulls a lawn mower blade.. think about that
 
dewbane said:
I figured old mower blades would be good steel, so I threw one in the forge, got it up to a good quenching temperature, and dunked it in oil.

Nope. Not hard at all.
Click to expand...
So how do you test hardness with a test like this, can you tell hitting it with a hammer or punch? File? or some kind of tester?
 
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