Cheap source of high carbon steel

Sylvrfalcn

Sylvrfalcn

Joined
Jun 4, 2002
Messages
3,930
Lawnmower blades. Yup, big old lawnmower blades. A buddy of mine who works for the maintenance department of a local school district brought me a whole bunch of 'em and asked me if I could use 'em for anything in the blacksmith shop. Could I ever! They're straight carbon steel with a very good carbon content. I've made knives, chisels, fire steels, awl bits, and lordy knows what else from them. Pretty straightforward stuff, I just heat 'em up red, throw 'em on the block anvil, and use a hot-set and sledge to cut 'em up into appropriate sized blanks. The steel forges, hardens, and tempers like a dream, and no more annoying file teeth to contend with (been making knives from old files for what seems forever). That's a big plus since my shop is totally non-electric, meaning there's a lot of draw-filing and hand polishing going on.
Now I realize not everybody has access to a blacksmith shop, but I reckon if a fellow was determined he could cut out his blank with a hacksaw and grind him a good knife on a bench grinder. Know any landscapers/lawn maintenance types? They'd probably give you an old mower blade for nothing, or at most buy 'em a beer or something. Give it a try, but be warned, if your lawnmower blade knife turns out nice all your buddies are going to want one. Ask me how I know.;)

Sarge
 
Egg-cellent info, Sarge. A cousin of mine once spoke of wanting to set up a forge... if so, I'll pass this tidbit along... maybe he'll let me borrow his hammer and anvil someday! :thumbup:
 
I agree with Bruise. :)

If you were going the hacksaw/bench grinder route, would it be hard enough to make a good knife? I always thought mower blades were intentionally on the softer side.
 
Hey, anytime you have something like this the kamis could use, send it to Yangdu with a note.. It will make its way to the Yeti state eventually.
 
hmmm... I know someone who works at the local school district :) (me). I might make a trip down to the maint. shop with some doughnuts...
 
Tohatchi NM said:
I agree with Bruise. :)

If you were going the hacksaw/bench grinder route, would it be hard enough to make a good knife? I always thought mower blades were intentionally on the softer side.
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They are fairly soft TO, probably around 45 RC (which by the by ain't far off from a mil-spec AF survival knife or Ka Bar). If you want 'em harder and ain't got an 18th century blacksmith shop like I work in, then use a barbecue grill and some wood charcoal. Not briquettes, LUMP CHARCOAL. Use a steady flow of air ("borrow" your significant other's hair dryer) to boost up heat output to around 1450, and when that dadburn hunk of steel hits cherry red, quench it in oil. Don't try for an edge quench like I'm doing with straight water in the slack tub, dunk the whole thing right into that oil or you're gonna start a fire. Test for hardness by observing color, you want to see a pearl grey color to the blade, and then run a file down it. The file should just scratch it but not bite in. To temper the blade you can use your kitchen oven like I've talked about a time or two here. Usually don't have to get most ovens up past around 425 degrees to hit a dark straw color or light bronze. Good enough:thumbup:

Sarge
 
Sylvrfalcn said:
Not briquettes, LUMP CHARCOAL.
Use a steady flow of air ("borrow" your significant other's hair dryer) to boost up heat output to around 1450, and when that dadburn hunk of steel hits cherry red, quench it in oil.

Don't try for an edge quench like I'm doing with straight water in the slack tub, dunk the whole thing right into that oil or you're gonna start a fire. Test for hardness by observing color, you want to see a pearl grey color to the blade, and then run a file down it. The file should just scratch it but not bite in. To temper the blade you can use your kitchen oven like I've talked about a time or two here. Usually don't have to get most ovens up past around 425 degrees to hit a dark straw color or light bronze. Good enough:thumbup:

Sarge
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As usual Sarge is spot on..... But remember that a, "Real Cherry Red" is more like a bright orange. The best way for rank newbies to achieve the proper temperature is to get a nice strong magnet, (so that you don't have to Guess when it's sticking too the steel) and heat the finished blade up to non-magnetic and then quench. That way it's pretty much fool proof to get a proper hardness for further tempering.
It's been my experience that most people think of "Cherry Red" as being the color of the sweet Bing Cherries at the worst, and closer to the mark, the smaller tart Red Pie Cherries..... But for hardening steel the color needs to be a bit brighter than even those. Us old hands have done it so long we can pretty well tell when we're there by looking at the color but unless the light in the surrounding area is just right when I go to harden a piece of steel I'll still use the magnet, just damned hard to go wrong that way.:thumbup: ;) :D
Another thing, mistake, most folks making a first knife make is going ahead and taking their blade to the finished sharpened state. If you should happen to do that you're gonna burn whatever edge you put on your knife plumb off! Different folks like their own amount of disposable steel around and over the edge of their knife blank. Personally I prefer about a 1/32" flat along the edge.
By the time I heat a blade up to quenching temp, harden it and then temper it and let it cool the disposable soft metal is fairly easily removed and the edge comes up pretty quick,------- usually.;) :foot: :eek: :D As usual YMMV..... :p


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Sylvrfalcn said:
They are fairly soft TO, probably around 45 RC (which by the by ain't far off from a mil-spec AF survival knife or Ka Bar). If you want 'em harder and ain't got an 18th century blacksmith shop like I work in, then use a barbecue grill and some wood charcoal. Not briquettes, LUMP CHARCOAL. Use a steady flow of air ("borrow" your significant other's hair dryer) to boost up heat output to around 1450, and when that dadburn hunk of steel hits cherry red, quench it in oil. Don't try for an edge quench like I'm doing with straight water in the slack tub, dunk the whole thing right into that oil or you're gonna start a fire. Test for hardness by observing color, you want to see a pearl grey color to the blade, and then run a file down it. The file should just scratch it but not bite in. To temper the blade you can use your kitchen oven like I've talked about a time or two here. Usually don't have to get most ovens up past around 425 degrees to hit a dark straw color or light bronze. Good enough:thumbup:

Sarge
Click to expand...
Awesome read thanks for the info just starting to build my forge .
 
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