Dixie Gunsmithing
Moderator Emeritus
Bob used to teach Gunsmithing at Lassen College out is CA. He retired, but still owns a gunsmith shop, and is involved with AGI and their video gunsmith courses.
Bob Dunlap--Metalurgy for Gunsmiths
- Thread starter Dixie Gunsmithing
- Start date
This is a page from a free 1968 pamphlet from Borg Warner.
It has an approximate equivalence of RC hardness to tensile strength in steel.
Having built cylinders from RC28 pre hardened ... should be 129 ksi tensile strength.
Starting with chamber pressures, going through the brass and steel calculating the stresses, and knowing the metal yield levels..... guns do not blow up when they should. Overloaded guns don't read the script. They refuse to blow up with one millisecond of the stress that should blow them up. They want more.
Dixie Gunsmithing
Moderator Emeritus
Gunplummer,
Yup, I've seen gobs of brazing and welds on gun parts. I've run into several forearm studs that were brazed back onto single shotgun barrels, by the so-called 'local auto mechanic', and I would not fire them, nor work on them. The problem is, if you work on one of these beasts, without replacing the barrel, and it burst after the fact, they can say you caused it, and sue, even though what you worked on wouldn't have had anything to do with it.
The wost gun I ever ran into, was a Winchester 37, that I was polishing for re-bluing. The breech face is a steel block, on these, that is welded to the U-shape formed steel frame, on both sides, and on this one, the polishing uncovered porosity in the factory welds. I had to grind out the bad, and run welds over both sides, then go through having it heat treated, to save the frame. The gun wasn't worth it, but it was a customers, and I got stuck with the fix. There's two versions of these, on how they're made, and the other has a round breech plug brazed into a formed frame. This 37, though, had to be the type with the welds down both sides.
I have built several parts back up with weld, then reshaped them, because the part was unavailable, and if it needed normalizing, hardening, and tempering, I did it. I try not to do that, if at all possible.
Yup, I've seen gobs of brazing and welds on gun parts. I've run into several forearm studs that were brazed back onto single shotgun barrels, by the so-called 'local auto mechanic', and I would not fire them, nor work on them. The problem is, if you work on one of these beasts, without replacing the barrel, and it burst after the fact, they can say you caused it, and sue, even though what you worked on wouldn't have had anything to do with it.
The wost gun I ever ran into, was a Winchester 37, that I was polishing for re-bluing. The breech face is a steel block, on these, that is welded to the U-shape formed steel frame, on both sides, and on this one, the polishing uncovered porosity in the factory welds. I had to grind out the bad, and run welds over both sides, then go through having it heat treated, to save the frame. The gun wasn't worth it, but it was a customers, and I got stuck with the fix. There's two versions of these, on how they're made, and the other has a round breech plug brazed into a formed frame. This 37, though, had to be the type with the welds down both sides.
I have built several parts back up with weld, then reshaped them, because the part was unavailable, and if it needed normalizing, hardening, and tempering, I did it. I try not to do that, if at all possible.
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Ok, at the risk of being really boring, here are a few links to useful information.
This .pdf is long / large and has a lot of table of compositions that may or may not be useful to you, but it is pretty complete:http://www.timken.com/ko-kr/Knowledge/engineers/handbook/Pages/default.aspx
If you are intereested in tool steels: http://www.crucibleservice.com/Products.aspx?c=DoList
For more general information, try: http://www.aksteel.com/markets_products/ - click on "Stainless Steels" for families, compositions, and properties.
This .pdf is long / large and has a lot of table of compositions that may or may not be useful to you, but it is pretty complete:http://www.timken.com/ko-kr/Knowledge/engineers/handbook/Pages/default.aspx
If you are intereested in tool steels: http://www.crucibleservice.com/Products.aspx?c=DoList
For more general information, try: http://www.aksteel.com/markets_products/ - click on "Stainless Steels" for families, compositions, and properties.
Gunplummer
New member
I always used the Jorgensen stock list and reference book. No where can I find any reference to quenching 4140 in water. I have never seen any directions to do such, other than end quench hardenability charts. I don't think it is 1040 because it seems the same all the way through. Your chart is OK, providing the material is heat treated properly. I remember a young guy that brought me a rifle he was learning to build on. It was a T-99 Arisaka (Could not get cheaper than that at the time) with either a 7x57 or .257 barrel. I don't remember. Anyway, he said as he test fired it the headspace was getting bigger. Turns out he welded a new bolt handle on and the area welded was wider than the original bolt handle. Basically, he headspaced on the soft welded area of the bolt handle and the bolt lugs were nowhere near the receiver lugs. The soft weld was slowly getting set back after each shot. He brought along 5-6 shells he fired. So, yes I agree, it takes a lot to blow up a gun, IF EVERYTHING IS NORMAL. Having a receiver that may crack just by dropping it on the floor is a little dicey in my book. I never wanted anything to do with '03, but is there not a reputation there for some receivers being too hard?
Gunplummer
New member
OK, so just how do you do that when color case hardening? As I said before, I never found any reference to water quenching 4140. It is too uncontrollable. I have seen photos of '99 Savages that are color cased. It is called color case hardening, not color all the way through hardening. Are we back to cyanide again?
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Jim Watson
New member
Mr Turnbull says he can case harden 4140 at a temperature just below its effective heat treatment temperature.
I don't know - never done color case hardening.
Pack carburizing I've done, and it entails long time heating in high-carbon material http://www.rosemill.com/category_s/48.htm cooling, then quench and temper - you may get colors but it is not specifically a color case hardening process.
If the 4140 part has few sharp corners (stress raisers) it might water quench without cracking but it is real chancy.
Do you need to water quench (as opposed to oil quench) when color case hardening? And - 4140 can develop real good strength on it's own, I can see wanting to case harden for wear resistance or appearance, but is the process commonly applied to 4140?
Pack carburizing I've done, and it entails long time heating in high-carbon material http://www.rosemill.com/category_s/48.htm cooling, then quench and temper - you may get colors but it is not specifically a color case hardening process.
If the 4140 part has few sharp corners (stress raisers) it might water quench without cracking but it is real chancy.
Do you need to water quench (as opposed to oil quench) when color case hardening? And - 4140 can develop real good strength on it's own, I can see wanting to case harden for wear resistance or appearance, but is the process commonly applied to 4140?
Gunplummer
New member
I am assuming we are talking below 1550 degrees. What are his thoughts about what '99 Savage receiver material is? That is what we are trying to find out here.
Dixie Gunsmithing
Moderator Emeritus
My suggestion, would be to e-mail or call someone who is very knowledgeable in case hardening. Jim mentions that Turnbull says he can do it, but what is his complete process? That's why I mentioned experimenting with scrap, to see what can be done.
I always sent frames off, that needed it done, so I couldn't say, and none were 4140. I understand the process, on regular low carbon steel, but 4140 is a different beast.
I always sent frames off, that needed it done, so I couldn't say, and none were 4140. I understand the process, on regular low carbon steel, but 4140 is a different beast.
Gunplummer
New member
Pack carborizing is pretty much like color caseing. I never used charcoal, just ash from all kinds of stuff I burned up. That is where the carbon comes from. I then threw it in water (Pack material with it) with an 02 source (Air hose) bubbling the water. Never drew it back, I figured it would wreck the color, but I don't know about that.
Gunplummer, I read (but do not "know") that one of the things besides carbon / charcoal in the pack carburizing stuff is barium carbonate, which comes from bone ash, and promotes formation of CO versus CO2. Raises carbon potential, making more carbon diffuse into the steel and less get lost as CO2.
I've also read that the air bubbling in the water quench is to promote temper colors - the actual color in the color case - by varying the oxide thickness that forms over the carburized case.
And - the guy who wrote that did not mention subsequent tempering / drawing, and implied that since the underlying steel was low carbon, they just quenched and left it at that - case was hard, core soft, no need to temper. But you would not do that to 4140, it would be hard and brittle all the way through (or very deep anyway).
I've also read that the air bubbling in the water quench is to promote temper colors - the actual color in the color case - by varying the oxide thickness that forms over the carburized case.
And - the guy who wrote that did not mention subsequent tempering / drawing, and implied that since the underlying steel was low carbon, they just quenched and left it at that - case was hard, core soft, no need to temper. But you would not do that to 4140, it would be hard and brittle all the way through (or very deep anyway).
Gunplummer
New member
Who in the world is knowledgeable about color case hardening 4140? This '99 Savage thing has been bugging me for years. Even if it is not 4140, it has a high carbon content. Charts and grafs are all well and good, if you know what you are dealing with.
Yeah Bobcat, now you see where I am coming from! You burn all kinds of stuff up and crush it down. Chicken bones, scrap leather, nuts, leaves, I even tried using peach stones and apricot pits because I heard there was cyanide in them. It takes forever to round up enough stuff for a good batch. I never could get the bright yellow and golds that I saw on guns that were cyanide cased. If you look at the newer charcoal done guns, there is not much yellow on them either.
Yeah Bobcat, now you see where I am coming from! You burn all kinds of stuff up and crush it down. Chicken bones, scrap leather, nuts, leaves, I even tried using peach stones and apricot pits because I heard there was cyanide in them. It takes forever to round up enough stuff for a good batch. I never could get the bright yellow and golds that I saw on guns that were cyanide cased. If you look at the newer charcoal done guns, there is not much yellow on them either.
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