Making chisels from O1 stock

[nick brigg]

I was just thinking the other day, i've seen a lot of people making their own plane blades, well what about chisels? has anyone out there made their own chisel from scratch?

[Mike Henderson]

You certainly can make your own chisels. After all, blacksmiths made the chisels for our ancestors.

But unless you have all the blacksmith tools (including a forge) to make and heat treat the chisels, those will be the most expensive chisels you can find.

Mike

[Jon Toebbe]

I'm not so sure about that, Mike. Precisely sized bar stock is pretty cheap. A hacksaw and a lot of hand filing / grinding in the annealed state just takes time and patience. I've been futzing around with a thick piece of 1/4 inch wide O1 that's starting to look suspiciously like a mortising chisel. There's lots of info on home heat-treating available out there.

Seems pretty do-able for the interested hobbyist. A good investment of your shop time? Only you can really decide that. I like making mortises more than I like making mortising chisels, so I haven't messed with my little project since getting some chisels as a Christmas present. Of course, what with work lately, I haven't had any shop time for mortises or chisels.

[nick brigg]

thats what i was thinking, i was looking for new chisels and i'm already ordering some metal to make my own plane blades...i just started thinking, why not chisels too?

[Dave Burnard]

It's simple enough (maybe time consuming) to make smallish chisels via stock reduction (grinding/sawing/filing away whatever doesn't look like a chisel). You can do simple heat treating with a propane/mapp gas torch or in the bbq with some extra air. There's lots of how-to's out there if you do some searching.

The usual warnings about slippery slopes and money pits apply to this potential hobby, so be careful!

[Joe Chritz]

I used to grind knives from precision ground o1 tool steel and send the blanks to a heat treat shop for pro treatment.

At that time minimum was $20 and I think that did something like 6 pounds of steel.

Stock removal isn't hard or time consuming but does take a bit of learning curve to get down right. I much prefer a 2" belt grinder for a task as such.

Joe

ETA: These are hunting knives not woodworking knives by the way.

[Greg Israelsen]

Prehardened and a wire edm worked very well for me.

[Ron Brese]

Actually chisels are a more feasible endeavor than plane irons when it comes to home heat treating. The amount of metal that has to be heated to critical temperature is a lot less than on a plane iron, so the results will most likely be more consistent than they would be in home heat treating a 2.25 wide 3/16 or 1/4" thick plane iron.

The other thing that needs to be considered when attempting home heat treating is that one mistake and you have a really bad burn. The ER visit alone would pay for a lot of professional heat treating. So if you intend to save money "be careful out there!"

Ron

[Ron Petley]

This is a great thread, I am going to give it a try this summer. You could make a 2 brick forge for quenching and heat treat in your kitchen oven, or with a propane torch. 01 would be a great steel to try it with, if you miss the hadening you can re do it untill you get it right.
I had posted a photo of a inexpensive forge in this thread;
http://www.sawmillcreek.org/showthread.php?p=757960&page=2
What I would like to know is what rockwell hardness is good for a chisel, and a lathe skew chisel, which I would think would have to be softer. Cheers Ron.

[Cliff Rohrabacher]

O1
Heat it to Cherry red. Yes you can use your eye.

Quench it in any oil - use a lot of oil

Shine it up to get a shiny surface and play heat across it till you get a slight straw color. That's about 56on the RC scale great for chisels
If you go to Peacock you'll have a 46 RC spring temper.

You can also temper to 56 RC in a good oven at 350-Deg F for a few hours. That'll do it rather nicely.

If you screw it up you should toss it or anneal it. Simply recycling the heat treat process is the wrong thing.
Annealing relaxes the crystal structure and lets you start over. Going straight to cherry red again sets up lots of internal stresses that tempering won't eliminate.

[nick brigg]

Now...what about getting the tang or whatever it's called into a chunk of wood? One technique i saw in david finck's book was to re-saw a blank, router a groove for the metal, then glue it all back up together, then shape the wood to whatever. hows that sound?

[Ron Petley]

The easiest way is to make it tapered and put a copper ring around the end of the wood, a short piece of copper plumbing pipe will make enough for a whole set, and will look good, the ring does not really have to be copper, any metal ring will do.
Cheers Ron.

[Trevor Walsh]

+1 to Ron Petley, I have a square taper on the tang, this gets burnt into the handle at a black heat little bits at a time until it's close. Then it gets happered the rest of the way in and done! I'm picking up some 3/32" O1 tomorrow to start on a tiny tiny chisel for dovetailing. I'll post some pictures here while I work.

[David Weaver]

I haven't made any chisels...well, at least not any intentionally nice ones. The thing that sticks in my head is that unless you're making push-carving tools or push chisels - light duty type things, a chisel that has a fairly substantial shank and a bolster is nice to have in a tanged chisel, and a socket and a tapered profile in a socket chisel. Those are hard to duplicate, and good chisels - probably better than you can make - can be had for cheap.

As Ron B mentioned, if you're going to heat treat a plane iron and it is relatively thick and wide, you need to have the heat to heat it from the interior to the edge, which is likely going to mean getting something substantial, like a weed torch. I haven't used a small furnace, so I don't know if you have any control over the ability to heat steel any way other than thinnest parts first and then wrap it with foil to prevent decarb. The process is intuitively pretty easy if you have a big enough torch and a dark enough room to see what's going on with the metal. But you need to have enough oil to swoosh around a hot plane iron, too, and that's likely a gallon at least, even if you're doing only one (don't put your hand in the oil to see how hot it got even after one iron, the hot oil circulates to the top of the can).

Specialty chisels (fishtails, etc) are great ones to start with, where a bolster or socket won't matter, and the tang being thin won't matter either. In fact, I can't think of a reason not to make the little specialty chisels with the cost that they fetch new.

George - I'm assuming you have made tanged chisels with a nice forged bolster before, how do you do it - is the bolster forged, cut and then tapered for a tight fit on the chisel shank, or is it all forged as one piece? Presume the handles are burnt in then up to the bolster?

[Jamie Bacon]

I've also thought of making chisels from time to time. Like some 18th century style square sided firmers, but not knowing how to make the bolsters without having a forge has always stopped me. I'd love to know how bolsters are made.

Jamie

[george wilson]

Those Blue Spruce chisels that everyone likes have no bolster. They have a tang,and the ends of the chisel where the tang starts is ground square. The ground square ends rest on a ferrule where the chisel's tang goes into the handle. This keeps the end of the chisel from just getting sunk into the handle till it splits. The handles are also full of a hard resin,I think.

This is not the best way to make a chisel,in my opinion,but it seems to work since the handle is hardened with resin. Bolsters are hard to make,and require special forming dies to be made up. I could recommend that the home maker grind or file the end of the chisel square on the end where the tang meets the chisel. Then,slip a THICK washer,which you may have to special order from MSC, over the tang,and file its hole square until it fits the tang where it butts up against the end of the chisel blade. A 3/32" thick washer would do well. You probably could make the washer out of thick sheet steel if you had to. Don't try to use cheap,cadmium plated hardware store washers. They are made of exceedingly soft steel,and are WAY too thin. MSC sells special thick steel washers for use around milling machines for clamping metal down. THEY MAY not come small enough to use on your chisels,though. If not,you have to make the washers out of sheet steel.

This washer will keep the tang from just being driven into the handle till it splits. A brass ferrule is NOT recommended unless you can make the thick washer. Use a steel ferrule. Brass ferrules will just get deformed where the naked butt end of the chisel bears against them. With the thick washer fitted,you can use a brass ferrule,because the washer evens out the pressure all around the ferrule.

Do NOT bevel the edges or the end of the chisel before you harden it. It WILL,no doubt at all, warp severely when you quench it. Harden and temper the chisel blade while it is still not beveled anywhere. Then,grind the bevels on the sides of the blades,and on the cutting end.

If you made the thick washer and fitted it with a square hole over the tang,AND it butts nicely,without gaps against the end of the chisel blade,you could file it octagonal,and file facets on it . Then,it will look like an old time chisel blade,and with GOOD fitting onto the blade,you won't tell the difference in it and a solid forged one.

The quench should be LARGE,as mentioned above. It should be large enough that a blade does not significantly heat the oil when it is quenched. Use at LEAST a gallon of oil,and that is a minimum. I use a 5 gallon quench,but that costs money,and might be too big for a home shop. Don't quench 1 blade after another unless you do have a large quench like I use. Give it time to cool between uses. It should be room temperature,NOT ice cold.

[Roy Lindberry]

The quench should be LARGE,as mentioned above. It should be large enough that a blade does not significantly heat the oil when it is quenched. Use at LEAST a gallon of oil,and that is a minimum. I use a 5 gallon quench,but that costs money,and might be too big for a home shop. Don't quench 1 blade after another unless you do have a large quench like I use. Give it time to cool between uses. It should be room temperature,NOT ice cold.

George - is there a specific kind of oil to use for quenching? Would motor oil work? And if so, what about used motor oil? Just thinking of ways to keep it on the cheap.

[David Weaver]

Used fossil motor oil is a known carcinogen. I don't want to get into a debate about how much of an implication there is toward using it a few times to quench, just throwing that out there.

And I'll add that everything that we had as a kid that needed a coating of oil got used motor oil out of an old railroad oil can. We saved everything and did not throw it away until we had nowhere to put it. When we had an excess of it, we used it to burn trash that needed a little help. I'm sure I've had it on my hands a lot, but will not be from this point on unless I am changing oil.

I can vouch for peanut oil. It is predictable, it doesn't stink, and it's widely available. It's not cheap here in the north, though.

[george wilson]

Used motor oil is a sure way to put a THICK,hard,black coating on your metal that is obnoxious to remove. It is an old way to "blue" gun parts. I actually used this same method to blue the rear sight for a pistol I was asked to repair by a chemistry TEACHER when I was in COLLEGE!! Try that today!!!!! I was carrying his gun around on campus to work on it. Not in the open,but in the Art Lab,where my sculpture teacher was,is where I fixed it. He knew about it,too,but no one was running around back then killing students,so no one thought anything about it. It didn't even occur to me that I didn't have a concealed carry permit,nor had I ever heard of one back then. The gun was not loaded.

If you could filter your old motor oil through some multiple layers of old panty hose until it is clear again,I guess that would be o.k.. It is the carbon in used,dark oil that gets deposited on the metal.

By the way,this is how some gas stations used to cheat customers,and may still do so today: They kept a 55 gallon drum out back,full of oil they had taken from engines. They wrapped a wad of women's hose around the nozzle to filter out the dark crud.

My old father in law worked for the then Esso company,putting in pumps and other equipment. He told me that if I ever saw OPENED oil cans full of oil neatly piled in a pyramid in the window of a gas station,it was used oil. We did have such a gas station near Williamsburg in the early 70's. I never got my oil changed there. Someone from their parent company found out about their oil,I guess,because they got closed down.

[Ray Gardiner]

I don't wish to divert the main subject of this thread, making chisels from 01 is well within the scope of an average home workshop, it's easy, and you can make exactly what you want, skews and special crank necked chisels.. and so on.. best part is O1 takes a beautiful edge.. good stuff.

The point I wanted to make is that you can get Polymer quenchants that are better than oil quenchants, the one I'm using is AquaQuench 251, you mix it with water and by varying the concentration you can get the quench rates from fast water quench to high speed oil quench, and at 20% concentration it's the same quench properties as high grade mineral oil quenchant.

Big plus is that it's fume free, no flames and very safe. It has some anti-corrosive properties, and lasts forever... of course peanut oil is just as good.... but if you are going to do a lot of heat treatment, it might be worth investigating.

Regards
Ray

[Ron Conlon]

If you could filter your old motor oil through some multiple layers of old panty hose until it is clear again,I guess that would be o.k..

I'm trying to think of a discreet way to ask an old lady for her panty hose...