Field guide to scrap metal? --asks a newbie

Australopithecus scobis snipped-for-privacy@die.spammers.die

The way to use a grinder spark test is to have some known pieces of metal to compare your finds with.

Get a piece of O-1, a piece of generic cast iron (strong yellow/white spark), a piece of run-of-the-mill mild steel, a piece of common high-speed toolsteel (dull orange?-not much spark). See how these spark.

For me, I wouldn't put much stock in spark testing beyond identifying the differences among cast iron, HSS, and mild steel--not that those are not important diffenences.

Old plane blades had a small section of high-carbon steel backed (welded to) by a mild steel body.

If I'm in a scrap yard, I look for the particulars of the steel dump. A heap of I-beams, or a heap of small boxes of toolbits. Assess the geography of the locus, as best you can.

FM

Go to this link. It's a list that may help you out.

Pete Stanaitis

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Austral> Greetings,

Try auto junk yards and get some broken leaf springs. Very cheap or free even. Still, it will be much easier to buy some nice virgin O-1 as previously suggested. Enough to make 10 or so plane blades will cost about $25.00 depending on the thickness and width of the bar. It comes

36" long by many different widths and thickness's. The nice thing about this tool steel stock is that it is nice and clean (no pits) and it is annealed, meaning it is as soft as it can be so cutting, drilling or grinding is relatively easy.

Glen G.

Thanks for the advice. New does look better. Thanks for telling me to buy annealed. I would love to try smithing, but not just now. So I have to make do with hacksaws and cold chisels.

Hey, avoid the cold chisels as the impact force will impart negative properties on the cut edge which could cause failures in heat treatment. Spend the xtra buck or so and get top shelf hacksaw blades, match the teeth to the material thickness and you will be amazed at how much control and little effort is required to saw this material. Good luck.

G.

May I suggest also getting a good high-tension hacksaw frame? The difference between a frame with an adjuster that gives good mechanical advantage over the olde cheape style with direct screweing on the blade mounts is somewhat stunning, if you have only used the olde cheape variety. A quality US-made version can be had for $30, a Chaiwan knock-off might be $5 or $10 depending on where you shop, and how much you care to deal with Chaiwan knock-offs, and the various places they have used cheaper stuff which looks similar to what they are knocking off, but costs less, and does not last as well.

Yeah, I use a Lenox frame that works very well. It has a good tension adjustment and a space inside the frame to hold extra blades. I think it cost about 18 or 21 bucks.

Spring steel is a great wood tool material, but stay out of the scrapyard. Old used springs are filled with microfractures in the grain, and no amount of forging or heat treatment will remove them. Look in the Yalu Pages for spring fabricating shops in your area and go over and see if they have a scrap end barrel. Spring stock usually goes for a buck a pound and is usually in a normalized condition, so machining isn't that bad, but it'll take more effort than mild steel. Spring steel here in the US is predominatly SAE 5160, an oil hardening chrome carbon alloy. It will get close to Rockwell C63 at full hard, and draw to around Rc55 at 450 degrees in the home cooking oven.

hope this helps...

Charly

Wow. I never heard of such a thing. But what do you expect of a woodchuck? (SEG)

OK, y'all have been so helpful, I'll go for another question: Moulding planes and the like come in matched sets, male/female. If I were making matched items of wood, I'd know how to do it. With metal, would one use a round hacksaw blade to cut the shape, then go at the pieces with fine round files? The two blades have to be pretty much an exact fit, because you have to cut the wooden part of a moulding plane with the matching plane's blade!

(I'm working on SWMBO slowly to get her used to the idea of a patio forge. S'mores. I'll tell her it's for making s'mores.)

Me, I'd grind to a profile line on both pieces, match the fit so they nest, then relieve the back bevel with files. Narrow belt sanders with the right belt compound will work quite nicely. Be patient and don't worry about the heat colors, you're gonna heat treat the finished tool anyway.

Charly

So I've heard but I have forged quite a few tools including cold chisels, center punches, special milling cutters, concrete chipping blades and others from both discarded coil and leaf springs and never had one break yet.

Ted

You've been lucky. I had one crumble on me. After my thumb healed, I pitched the rest and bought virgin stock. 5160 is dirt cheap new, why take the chance? For hand-driven stuff like a wood plane, you'll probably get away with it. For motor-driven stuff like shaper cutters, I wouldn't bet MY ass on them. I've seen what a shaper blade can do to a boxcar, can you say 'howitzer'? Buy new stock, be safe.

Charly