So I decided to get knife making out of the system today. It is going to be a throwing knife. I made it from a piece of a Bellota farrier rasp, if i remember how to spell it correctly. I think it turned out ok for a first go. I started to grind it and now I think it is ready for heat treat. Anything you think I should do grinding before I heat treat it? Also, what is a good color to temper it to since it will be a throwing knife? Thanks

 

Maybe you'll get lucky but many Bellota farrier's rasps are case hardened.

You may want more polish so you can see the colors run easier when you go to temper it. Remember it's easier to grind before you harden it, then afterwards.  You don't want a thin edge just yet, as that will burn off easily when heating, but you want the majority of finish work done so all that is left is the final edge.

I would try to harden a smaller piece of the same rasp before you do a lot more work on it.

Ok thanks. Great I hope this wasnt case hardened should have tested. I read something that it wasn't. I broke the piece of the file by hitting it with a hammer over the edge of the anvil, not sure if thats a good sign? Thanks

I'd leave a throwing knife dead soft annealed, you'd rather it bend than break if it hits a rock on the ground. Throwers don't really need an edge, just a point.

Oh that's a good tip of advise thanks

 

What about handles, any ideas for a throwing knife handle cause I know wood might break.

14 minutes ago, Michael said:

I'd leave a throwing knife dead soft annealed, you'd rather it bend than break if it hits a rock on the ground. Throwers don't really need an edge, just a point.

So do you mean let it air cool or cool it in sand. Maybe do it a few times? Thanks

37 minutes ago, Forging Carver said:

 

So do you mean let it air cool or cool it in sand. Maybe do it a few times? Thanks

Normalize, air cool, a few times from progressively less heat a bit over non magnetic right before it changes and a bit under 

I'm not sure which to do. Some say to leave untreated but others on blade forums say to heat treat.

I'd say quench just the tip, and temper the tip end 30mm (inch and a 1/2 ish) to a blue temper. For a thrower you want to be able to get a fairly strong tip sharpened in for penetration. Leaving the rest of the body annealed/air cooled soft is good advice.

4 hours ago, Frozenthunderbolt said:

I'd say quench just the tip, and temper the tip end 30mm (inch and a 1/2 ish) to a blue temper. For a thrower you want to be able to get a fairly strong tip sharpened in for penetration. Leaving the rest of the body annealed/air cooled soft is good advice.

Seems like your best bet, remove forging stress and decrease grain size then ht tip so it stays sharp could clay the rest of it if it's hard to heat just the end

Nah I'm the master at heating only one end. Only when I just got my new coal I could heat one end!

3 minutes ago, Forging Carver said:

Nah I'm the master at heating only one end. Only when I just got my new coal I could heat one end!

Oh yea, what size did u end up with.

Size of the knifeand? The knife around 6-7inches

 

8 minutes ago, Forging Carver said:

Size of the knifeand? The knife around 6-7inches

 

The coal but yea that 2 

The smithing coal he bought at Peoples down the street from Andrews shop is from about 3/4" down to fines, though there are a few occasional bigger pieces.

5 minutes ago, DSW said:

The smithing coal he bought at Peoples down the street from Andrews shop is from about 3/4" down to fines, though there are a few occasional bigger pieces.

Ah ok, weaverland got a load of nut insted of pea this time, still burns good, don't like the size though

I need to try and get to the shop later today. I'll try and take a pict of what I bought there if I remember.

I'll take a pict. The coal is great and burns hot! Only issue is that I didn't realize how much bituminous made smoke first starting out. I was afraid the fire depth was gonna come or a neighbor was gonna complain! But it's much better than anthracite. Will antler work for a throwing knife handle? Deers ram their heads in trees all the time, so I must be strong. Thanks. Here's the coal and what the Coke looks like and how hot it was! What do you use as a air flow cause I think my hair dryer is too much. Thanks

Unlike anthracite, you don't need an air blast full time with Bituminous. I have an air gate on my blower that I can close down to restrict the air when I don't have steel in the fire, or when I want a slower heat. Some simply turn the air on and off instead. I know a number of people who use one of those HF foot switches to turn their blower on and off as needed.

 

The coal in the last pict is obviously still green. You don't get flames like that when the coal has coked typically. I keep a pile of coal right up against my fire pot that is slowly coking. I drag small amounts into the fire as needed and that keeps down the smoke. For starting I use coke left from the last fire plus some new fresh coal. I try to get a flame like you have as soon as possible to burn off the smoke, usually by poking a hole in the top layer to let the flames out. I know people who will burn a piece of newsprint in the back of their forge under the chimney to ignite the smoke when starting up as well as to increase the draw until the fire heats up.

you could make a damper to solve your air problem and antler is very strong but I like the bare metal look and the texture that the rasp teeth leave but if you want to make a handle for the knife I thing antler would be the best bet if you can find some

Dsw can you send me a picture of your forge with the airgate. Also what type of blower so you use? Unfortunately I only have a brake drum as my forge, I need to make or buy another one. Thanks

Thanks nick. I will see what antler looks like on it, but I think the bare metal looks pretty cool too. I have a piece of antler from when I used to flint knapp. My brothers friend is a hunter so I can get the entire set.

Add coal before you take it apart so you have some fresh coke to start the next fire with

RE: handle. You want it as smooth as possible for a clean release for a straight or rotational throw. You also don't want to add much weight to the handle end.
I would be inclined to leave the handle portion as is, possibly grinding the teeth down a bit smoother. you could dip it in 2 part epoxy to fill the gaps between the teeth and then sand it back to be perfectly smooth.

ok. From grinding, the edges are sharp so maybe i will file them done a bit too. The balance is about down center, but I think more weight is in the handle. I am drilling a hole instead of punching so that it will remove some material.