hard nose sear

[David R. Pennington]

Working on a lock and picked a sear blank out of my drawer. It looks like a large Siler and it had never been drilled or filed. Looks like about the right size so I spotted the hole and drilled. The drill cut fine almost all the way and hit a hard spot and stopped dead. I heated it red and buried it in the sand bucket overnight. Seems even harder. So I heated a junk tomahawk head red and buried it in the sand first to preheat the sand and put the sear inside a small section of pipe and heated the pipe and sear red and then buried it all overnight. Still can't cut it. File skates off! I guess I will just forge out a blank and start over.

[D. Taylor Sapergia]

I had a tumbler like that.  I ended up building a little birch wood fire behind my shed, and when the coals were good and red, I heated the tumbler up to orange with my portable oxy/act. tanks and dropped the piece into the coals.  Five hours later, I fished out the metal, and it was soft enough to cut with a knife.  Thanks to Tom Curran and Cody Tetachuck for the advice.

[WKevinD]

I had a few sets of sword castings (from the Rifle Shop) and was drilling out pommels and hit an inclusion, a piece of slag of some sort, burned up my drill bit (twice), moved to another.

[Mark Elliott]

It is experiences like that which have driven me to do all my annealing in my heat treat oven.   I just bring the oven up to recrystalization temp and unplug it.   It takes all night for it to cool down, and I have a nice soft piece of metal the next morning.

[bob in the woods]

I throw them in my wood stove in the evening, and fish them out in the morning after the fire has died down. Empty the hot ashes into a metal bucket along with the steel parts and let cool till mid day or so.  They are as soft as can be.

[LRB]

  David, there is a good chance of that sear being 01 steel. If you have a HT oven you can spheroidize anneal it by soaking it at 1300° to 1350° for an hour, then let cool to below 900° at a cooling rate of about 50° per hour. At that heat, the carbon will form spheroid shapes instead of plates, which will allow much easier cutting. If you have no HT oven, you can slowly heat it at least 3 or 4 times to a very low, just barely showing red color and let cool. This usually does enough to get by with. All steels with more than .8% carbon will respond to this much better than the common anneal, which allows the increased carbon to form hard layers/plates as it cools. I have an oven, but most often just use a torch in very dim light. Easier and faster. If the heat goes past non-magnetic, 1414°, this will not work.

[Bob Roller]

Another annealing method I like is to use the acetylene torch and then drop the part into hot sand that has been preheated on a stove and let it all cool off together.

Bob Roller

[PPatch]

Ho boy, similar to DavidR I have a L&R frizzen that nothing will touch, files skate, dremel tool grinders touch it but then you're left with ripples which can't be smoothed. I intend to anneal it. Would the annealing process be the same as you guys are recommending for that tumbler? Will MAPP gas get it hot enough?

Not intending to hijack your thread David.

dave

[Bob Roller]

Use a 5 inch diameter bench grinder to smooth the L&R frizzen. That Dremel grinder is no good at all for this job.That Mapp gas gets hot but is short lived in the miniature tanks.I have one and haven't used it for years.
 Bob Roller

[mattdog]

When I get tumblers back from the foundry (6150) they immediately go into the oven and I take them up to 900 deg. and let them cool as slow as possible.  This saves me a lot of frustration and tooling.  Frizzens (1095) get baked at 1500 deg. for an hour before any drilling or grinding.  This has become routine now. 

In Dave's case I would do similar to what Wicke does, multiple heats with OA rig and cool slowly.  Tedious but sometimes you just gotta do what you gotta do. 

[Dphariss]

When I get tumblers back from the foundry (6150) they immediately go into the oven and I take them up to 900 deg. and let them cool as slow as possible.  This saves me a lot of frustration and tooling.  Frizzens (1095) get baked at 1500 deg. for an hour before any drilling or grinding.  This has become routine now. 

In Dave's case I would do similar to what Wicke does, multiple heats with OA rig and cool slowly.  Tedious but sometimes you just gotta do what you gotta do. 

No oven? Polish and heat to blue then slowly take the temp up till the color fades away then let cool. May work. For this hole a carbide drill will work but must have the part held tight in a drill press vice any movement will break carbide. High tech tapping lube will sometimes allow hard parts to be tapped. Teflon, Moly lubes can help. But its still risky.
Heating these irritations to red is sometimes a mistake.

Dan

[Dphariss]

I would also point out that the part could contain almost anything as an inclusion or alloy so its difficult to find a rational way to anneal the thing. These are not from Ruger's Foundry after all. ML castings are often full of junk and casting flaws and a few slip out to the end user. As an experienced friend once said "you bought a casting and didn't  buy a welder to go with it?"

Dan

[JBJ]

I had a similar experience with a lock casting and I "think" that my issue was allowing the drill to momentarily to spin without cutting. In this instance, I may have allowed the alloy to "work harden". Finally annealed it in a charcoal fire that was allowed to slowly burn itself out giving the part a long soak period and cool down. Re started the process and used a tapping/drilling fluid and made it through. Just glad I did not have to tap that particular piece because I think that it would have hardened again! Could have been that I hit an inclusion but I really think I allowed the piece to work harden. Not being a metallurgist, just my thoughts. How often do we really know what alloy we are dealing with? Not often!
J.B.

[LRB]

  If it came from Chambers, it's 01 for internals, 1095 for frizzens. Both will respond to spheroidized annealing. I don't recall what he uses for the plates.

[Bob Roller]

Ruger's Foundry should be the gold standard.I doubt if they use bubble gum molds and pour anything that will melt.

Bob Roller

[JCKelly]

Probably not this problem, but Experience says when asking a foundry to make something, have them cast it of the metal they most commonly use. All foundries, all alloys.

Otherwise you may get some interesting alloys no one ever heard of.

Reason - if they melt your, say 1018 or 4140, in a crucible previously used for stainless steel you will get an air hardening tool steel that is really "fun" to work with. I found my experience with this quite interesting, but then, I was not paying for it. The foundry needs a "wash heat" in between the stainless/whatever and your part. Most unlikely to happen (it won't) for low quantity production muzzle loader parts.

[mattdog]

 "Most unlikely to happen (it won't) for low quantity production muzzle loader parts."

I'd hate to see this misconception continue.  I know that the foundry that I use most often also casts parts for the other "big outfits" in the muzzleloader industry.  It's not so low quantity when you think about it.  They aways use a new ingot, not scrap or fall off swept from the floor.  They know that they are making gun parts and they'd better do their best work. I'm not saying that bad stuff never happens only that we all take responsibility to produce the best we can with what we got, including the foundries.   

[David R. Pennington]

I did like you said Bob, I heated it and let it cool slowly in hot sand. Second try I preheated the sand with a red hot tomahawk  head buried in the bucket first. I have just about decided it will be easier to make a new one than keep fooling with this one. I am tired of sharpening drill bits. Cold weather I use the wood stove ashes but it's been too hot for that. The steel for the tumbler blanks I brought up to heat in the forge fire, buried them good in the fire and let the fire go out on it's own. About 20 hours later they were soft as could be. I just didn't want to fire the forge for a little sear.

[jerrywh]

 Place the sear on a large  thick piece of steel and heat the whole thing up to a red heat. You need a piece big enough to hold the heat for a while. 1/2" thick and a couple of inches square at least. Then it will take a while to cool. Heat it from the bottom until the big piece gets red hot then let it cool. Hot sand is still cool enough to harden a tool steel part unless it is above 800 degrees. Some work hardened parts will not anneal so you might have to grind off the surface of the hard spot with a dremel or drill it from the other side. There is always a way. Do you have a carbide drill. Enco has them cheap. Buy more than one they break.