Cock jaw teeth

[Dennis Daigger]

I'm hoping to reestablish the teeth on the jaws of a cast lock. I made a sharp pointed punch from O-1, hardened and annealed it but the tip blunts quickly so am looking for ideas for doing this some other way.
Dennis

[45-110]

Sounds like the cock needs to be locally annealed first.

[D. Taylor Sapergia]

Yes, you're trying to raise teeth on a case hardened cock and top jaw.  Anneal both the top jaw and the head of the cock, then punch up new teeth.  Don't try to puch teeth with a dull or rounded punch...must be needle sharp but coarse enough not to collapse/bend/break.

[Scota4570]

I made my tool out of a 1/4" high speed lathe tool bit blank. 

[smart dog]

Hi Dennis,
I use a round bottomed die-sinker's chisel I bought from Brownells.





dave

[Rolf]

Where can I buy a round bottomed die-sinker's chisel? Can't find them at Brownell.

Best regards
Rolf

[smart dog]

Hi Rolf,
I bought mine years ago and I just checked online.  Seems nobody has them anymore except an occasional find on E-bay.  You should be able to make a very similar tool with a round blank of high carbon steel.  It is a shame because the chisels are invaluable for 3D sculpting of metal efficiently.

dave

[Birddog6]

Warning:  Draw a pattern very close & measure the angle of that cock precisely, Before you anneal it & punch on it. 

If ya don't have 100% support under the Jaw (not the shank) the Jaw of that hammer & start punching on it    Unless you really know your locks & what makes them work Good, you will have the  angles off on that cock & you will have a sumbitch of
a time getting it back right.   No need in asking how i know. 

[smart dog]

Hi Keith,
Moving the angle of the cock, even when annealed, has never, ever been a problem when cutting teeth.  It would take way more force to do that.

dave

[Dennis Daigger]

Thanks for the responses.

Taylor-the cock and top jaw were as-cast and not case hardened but I did go back and try annealing. My punch failed again and wonder whether the point because of the small mass has undergone some metallurgic change that keeps it from properly hardening.
 
Keith-to prevent flexing of thin parts Thermo-Loc provides sufficient support when moulded around it and then secured in a vise.

Dave-several weeks ago I was looking for a die-sinker's chisel like yours so that I could do some sculpting on the breach end of a pistol barrel that I'm working on and after several hours of frustration found that there were simply no die-sinker's chisels available anywhere any more. Die-sinkers rifflers everywhere but no chisels. I bought a flat tipped one from Brownells some 20 years ago for shaping shotgun balls and at the time they did carry several tip configurations. Wonder what folks use for this kind of metal removal and sculpting now?

I have some 1/8" carbide graver blanks and will try to shape one into a punch.
Dennis

[Scota4570]

Carbide does not handle shock well, high speed is a better choice. 

[44-henry]

Try hardening your punch again and than test with a file. That will tell you quickly enough if you are getting it hard or not. You should do the same on the jaw to make sure it is truly soft enough. If everything is as it should be and you are still having problems it is probably an issue with your punch/chisel geometry.

[kutter]

The jaw of the hammer MUST be secured so that there is no flex, movement, bounce, etc.
If it does while your are hammering on it with your chisel, the point of the chisel will fail.
Vibration of the workpiece is the killer when doing any engraving/chasing/chisel work.

Carbide will work, but you all carbide is not the same. Carbide 'gravers' are not the same carbide as that used in other carbide tools.
Besides, carbide gravers are used to defeat extremely hard and tough steel. That's not the problem here.
A Carbide Graver will break it's point just as quickly when used against a surface that is not solid.
About the only good thing about a Carbide graver bit is that when they do fail, they don't just nub over to a dull point surface. They fracture and actually give you a sharp surface once again but it's usually very rough, uneven and off center of course. Some engravers don't seem to notice from looking at their work.

If the hammer jaw is secured tightly and supported correctly so there is no bounce or vibration, then most any steel cutting chisel will do.

Those little Die Sinkers chisels they sell are OK for finer work. But they are really kind of light for this type of stuff.
You want a HD chisel and hammer to be able to punch up a burr with but a couple strikes. Maybe even just one.

You can  use a plain old 'cold chisel' for the job. Yes those large things with the big flat cutting edge.
A good quality one will easily cut soft steel.
Most every one has a few of the old ones around that have seen hard use and we wonder why we still have them.
The large mass of the chisel itself is a good thing as it won't bounce back when struck. It's a dead blow with a heavy hammer against a solidly secured surface.
That's what you want. ,,and you don't have to strike the chisel very hard either. The heavy mass of the hammer pluss the chisel do the work.
It's the same idea used to hand 'stitch' a file surface.

Sharpen the old chisel's cutting edge to take advantage of one of the  ends of the flat edge.
Grind the face to approx a 50 or 60* angle going fom one edge up to the other.
Add a little heel angle under the point so the chisel has some lift. Shape the point any way you want,,a V or a U,,doesn't matter.
It'll throw a burr up like a rough cut rasp with a couple hammer strikes.

[smart dog]

Hi,
That "little" 1/8"  round bottomed die sinkers chisel works great at this job.  Too bad you cannot get them anymore. You are not mashing up a burr rather cutting one.  Needs a lot less force.  I done this job on every lock I make or use on a gun over a couple of decades.  Moreover, when you examine original locks you can see that the big musket locks were cut with some wide round bottomed chisel while smaller pistol locks have dainty little teeth cut with gravers.

dave 

[Dennis Daigger]

Thanks again to everyone for all of the info. I found that I had not really annealed the parts as I had thought and when looking for a method for doing this I ran into a Taylor post that confirmed something he had learned here. I soaked my parts for about 1 1/2 hours in a bed of charcoal in a small Weber that had a large heap of additional charcoal on the top. I then covered the entire pile with wood ash from the stove and this is now cooling. I'll take it out this evening.

Scota4570-yep, the carbide chipped on first strike. I didn't think I had any HS tool steel but found a stray adjustable reamer blade and made a cutter using Dave's round profile and got good results. Here is the result on a scrap of 1018 but I think I'll need to use a shallower angle when cutting. Also used a real hammer instead of the small bench hammer for light tasks.


I don't know if others have used Thermo-Loc but an engraver friend told me about it and it makes for a rigid foundation for all kinds of work and is a great way to hold small parts for operations such as milling.
Dennis

[Bob Roller]

Spring loaded center punch worked for me and also a coarse cut checkering file.
Bob Roller

[RAT]

One of the first things I do after disassembling the lock for the first time is anneal the cock and top jaw. I heat them up with a MAPP torch until orange and put them in a coffee can full of ashes to sit overnight.

I just use a normal square graver to raise the teeth. I can't engrave worth anything... but the gravers work great for raising teeth. All you need to do is drive them in at a steeper angle until they "stick"... Then pull it out. You don't need to use a lot of force. All you need is a little burr. I drive the graver with a light rawhide hammer.