My first knife - What kind of metal is this?

E

EAPellow

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Aug 16, 2012
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Originally posted this in the Custom and Handmade Knives forum, but realized this is a more appropriate place. Still new here.

I just finished shaping my first knife (well, the first to come this far). I have a lot of fine filing to be done, and have to decide how much to profile the blade. I did everything with an angle grinder, cut off wheel, drill press, and a round bastard file for the two large holes as I didn't have a 1-inch bit. My goal was to make a knife/hatchet that had enough weight for light-duty chopping, or banging on the spine with a log, as well as more delicate knife work. The handle can be held near the end or near the blade, and the large holes let you grip the head of the blade in different ways to draw the knife at different angles. Those holes aren't placed as well as I had hoped though.

I have never heat treated a blade before, and, though I have a downdraft fire pit that I built for a friend that might do the job, I want to get this one perfect, so I may just see if there are any smiths in my area.

My question is, do any of you know what kind of steel this is? I cut it off an old L-beam, and you can still see the remnants of "Phoenix USA" on it. I'm hoping that if I know what grade of steel it is, it will help me heat treat it.

Also, any input for a beginner? I'm looking into making some carving knives for a friend, maybe even a crooked knife, but I also have knife I started awhile ago but never cut the tang for - a 6 in. sawzall blade ground to a 20 deg edge with a 3 blade. Picking through my wood stock to see what might fit it... have some ironwood blocks that I cured that might be nice.

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My one though it cutting out the portion in between the two large holes. This would allow for the versatility that I was hoping for, but add more work onto the project when I no longer have access to the angle grinder's cutting wheel. I wonder, would that compromise the strength at all?

The other thing is the balance: right now the balance point is at the width of metal between the second large whole and the notch at the top of the handle. Cutting the two holes into one large ellipse would shift the balance over the top of the handle. Given that might intended uses include light chopping, would this be a no-no?

Thanks for anyone's input
 
It is probably 1018 or A36 or something similar. Most likely, it will not respond to heat treatment in a way that will make a good knife. It is practice though. Read the stickies at the top of the forum to help you along your path. If you haven't filled out your profile, do so. It helps others in answering your questions and giving advice.

Try to get some 1/8" 1075 or 1084 to start with.
 
Rats. Maybe I'll try heat treating it anyway just so I have a first attempt at that under my belt. I went ahead with this because I had a week of access to the angle grinder and drill press at someone's house, and don't, as of yet, have a workbench and suitable vise in my apt. I found the scrap beam, and drew up the knife overnight.

I'll have to get a decent bar of metal sometime to work on. This stuff is 1/4" which is exactly what I wanted for this design, but 1/4" is way too hard for me to work on at home other than just filing. After I finish moving in here, I'll have to design a decent work room.

Thanks for the input, I've read a fair amount on what types of metals to use and which to avoid, but I never heard anything about structural steel like this, so I just went ahead with it. I'll peruse the stickies to see what other guidance they have.
 
I used to think hand filing a blade would be only slightly better than self torture. It really isn't that difficult with an annealed piece of steel. A whole lot can be done with a hacksaw, regular drill and some files. Look for one of the threads on page one or two started by "peppen108" a newbie that just jumped in with both feet and a bunch of files. A piece of 1084 from Aldo is about $20 including shipping, and if you can't do the heat treat yourself just yet, send it out. No shame in that, and you'll have plenty to learn, buy, scrounge and do before you hit the books with heat treating.

Don't bother to heat treat that, it will just waste fuel. Put up a board or a log in the woods or yard and have some fun, or use it as inspiration for the next one or few.
 
Thanks for your input, I'll give that a look. I really don't mind filing that much, just need to get a table to work on.

So there's really no method of heat treatment that would help this thing? I'm guessing it's because of the low carbon count if it's 1018, other than that, it's about the same as 1084, but with maybe 20% of the carbon content. If this thing isn't going to be practical at all, I guess I'll have to use it as a prototype and get some 1/4" steel to make a new version. That's a shame, I'm still going to end up hacking a log with this.

If I ever do try and heat treat anything, I have access to a fire pit I built for someone that doubles as an updraft pit kiln for pottery. It's an elliptical stone pit about 2 feet tall, and has an 1/8" steel plate going across one level of the rocks, about 6" from the cement slab that it's on. Tons of holes were drilled in the plate, and there's a wide opening in the rocks at one side of the bottom, allowing for a draft to come up from the bottom. It gets hot as hell, and you keep feeding wood in and it keeps burning it up. Do you think this might work for at least the first step of heat treatment? I don't think I'd get the temperature controlled enough for tempering though.

So, impractical metal aside, what do you think about the knife itself? If this is going to be a prototype, I want to improve upon it.
 
If you can get the steel glowing a bright red color you can heat treat 1075 or 1084 steel. Use your blade to see if it will get that hot. If it does use one of those new rare earth magnets with a hole in it suspended by a wire a couple of feet from the fire pit. As you heat your steel up and it starts glowing, Carefully, using a long set of tongs and making certain no one is in the way hold the glowing blade near the magnet. If the magnet is not attracted to the steel you are above the magnetic temperature of the steel. Let the blade cool until it attracts the magnet and note the color of the glowing steel. This is the magnetic transition temperature. A 1075 or 1084 blade should be just a little above (a little brighter red) than the color when the blade becomes non-magnetic.

Your blade looks like one of those eskimo tools (I forget the name) with a handle on it. Could work well for skinning and scraping hides. Maybe scarping and smoothing wood.
 
Bo T, I did have uses like that in mind for the ergonomics of this piece, though they didn't completely come through. I want to use it as a light hatchet but still do some light woodworking.

I know about the magnetic temperature treatment, I've read a fair amount here and there, it's just a matter of me actually trying this. I'll see what some smiths say if I bump into any this weekend, but I might use this as a practice tempering piece. I have no doubt the pit I built can get hot enough to demagnetize the metal, it's just the tempering process that I'd be weary about.
 
You need to go back and read a bit more I think. I'm seriously trying to help, not being a butt.

Tempering is easy. If you have an oven, you can temper high carbon steel, like 1084. A regular oven won't wok for some (most) super high alloy stuff because it won't get hot enough, like CPM-3V, M390, etc. 450 is as high as you need for 1084.

Hardening is a bit different. It involves taking the steel above the Currie point, that is to say, nonmagnetic. Full austenizing temperature is higher, around 1500*. This changes the molecular structure of the steel. Get a book called Metalurgy for Nonmetalurgists. It's good stuff.

Here is a heat treat schedule for 1084, per Stacy Apelt, our Mod.

Quote:
A torch isn't really a good way to HT, but it will work for 1084.

Here is a basic HT regimen forn 1084:
1084 HT:
refine grain and normalize -
heat to 1500F and air cool to black, then quench to cool
heat to 1350F ( just non-magnetic) and air cool to black, then quench to cool
heat to 1200F ( still magnetic) and air cool to black, quench to cool
Straighten any warp or twist

Austenitize-
heat to 1500F and hold long enough to allow the blade to be evenly heated
quench in a fast quenchant (or as fast as you have, canola will work for all but big blades)
Check for warp after holding in the quench oil for 5-8 seconds. Straighten immediately. Stop after about 20-30 seconds, as the blade will be too cool and may break.

Temper immediately at 450F for two hours, twice. Quench in water to cool between temper cycles.
( If there is any warp after the blade cools, it can usually be straightened while at tempering temperature. Let it heat for 30 minutes before any straightening.)
End quote.

There you go. Now get to hacking that blade you made. It will work ok for testing ergonomics and such. Then order some 1084 and make one to harden.

This is just me, but if I was going to make one like that, I might be inclined to use 5160 rather than 1084. Aldo can still hook you up.
 
If you got the steel from a structural piece of steel, depending on how old it is, it will most likely be A-36 or something similar. The shocking part is A-36 can be hardened, BUT you need very good control of the temperature and as fast a quenchant as you can get your hands on, and it still won't be anywhere near as hard as a normal knife blade. Just for reference, when I say fast quenchant, ice brine is as SLOW as I'd go. Hardness would be somewhere in the mid to upper 40's HRc. Yes, it is the lack of carbon that limits the hardness of such steels as 1018 and A-36. FWIW, if all you want to cut is meat and soft veggies, this type of steel can be effective, but you need a much thinner piece than 1/4".
 
Thanks for the input both of you. I do need to read more. It'll be easier for me to remember it all and get it straight in my head once i put some of it to practice.

I do have a gas oven that I could use for tempering, but my girlfriend might kill me, and my landlord owns it :P
I've got friends who work with bronze pouring looking around for some smiths in my area that can help me in the future.
 
EAP, when I tempered my first piece, I did it at work for that very same reason.

If you use 1084, use canola oil to quench it. When you temper it in the oven, it will smell like popcorn. Seriously. If you use some other, less effective quenchent like ATF (please don't), then temper at your mother-in-law's house. ;)
 
I don't have a mother-in-law, but there are some people I don't like... Maybe I'll go over their house and quench in pitch black used motor oil
 
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