Question: How to Naturalize steel for engraving

[jimzim75]

I was wondering if anyone has taken the temper out of steel so it can be engraved. I learned the
fundamentals in school, but I have never done it before.

I have a kiln, so is this just a matter of soaking the steel in heat for 24 hours till it spherodizes with a
gradual cool down? Is it simple better to send out the item to a company that does this sort of thing.

Any help would be greatly appreciated,
thanks,
Jim

 

[John B.]

Jim, you've got the basic principal right.
Couple of things I would consider.
Usually you don't need 24 hours, just bring it up to critical temp and give it a slow cool, like you said.
Don't do this on any stressed gun parts, of course.
With a kiln you will get a lot of heat scale.
If this would be a problem it helps to wrap the steel in Stainless Steel foil and include a tiny piece of paper inside the wrap to burn off the oxygen.
For no heat scale at all send it out the a heat treatment company that has absolute oxygen free, inert gas ovens.
Hope this helps. John B.

 

[Bill Burke]

hello My name is Bill Burke and I am a knife maker by trade. I am an American Bladesmith society master smith. having said that. it is not neccessary or really desireable to bring your steel all the way to criticle. the most machineable state of steel is when it is spherodized. This differs from annealing in that the steel is heated to a temp from between 950 to1350 degrees F. and held for a sufient amount of time and then cooled slowly. as was stated above do not do this to any stressed gun parts. for knife parts i use 1250 degrees and hold pieces for two hours and then leave in the oven to cool slowly in the oven. wrap in heat treating foil with a slip of paper along side the piece to control scaling. I am not trying to cause problems or to step on toes here just help where I can and hopfully you all will help me with learning to engrave.

 

[jimzim75]

Thanks for the info. I was talking to the local guy in town and he said I should try it
myself. He does machining and heavy steel.

With your help John and Bill, I think it's worth a try. The parts worth $38.00 and there is
plenty of them. So I'm not to worried if it goes south.

Jim

 

[auto45lee]

Use a small section of titanium in the foil wrap it works a lot better than the paper trick. I have used both my blades come out of heat treating a lot cleaner with the titanium.
www.fergusonknives.com

 

[jerrywh]

What does the titanium do???? please.

 

[auto45lee]

This was the instructions that came with the heat treating foil. I gave it a try and it works I do not know how. You can use it over and over again. I am using 6AL4V 1"x3" section for a knife blade.
Lee F.

 

[BrianPowley]

I've annealed many parts in my wife's self-cleaning oven, including several Erfert and K date Lugers.

For what it's worth, a self cleaning oven can heat to 800-850 degrees.
A typical cleaning cycle is 3-4 hours, but the oven won't unlock for several more hours.
Those are pretty decent parameters for annealing steel.

I usually put the parts on the center rack around 9:00 p.m. , hit the button and forget about 'em.
I take the parts out the next morning and they are quite soft and my wife's oven is clean (Win-win?)

As far as foil wrapping the parts with paper or not wrapping at all---I've done both and found out that either way, the metal is discolored and needs sanded and polished. Any scale I've encountered without wrapping is usually light enough that it wasn't a headache to remove it, but wrapping doesn't take any time at all.
That tip about using titanium instead of paper sounds interesting....
My two-cents worth....

 

[Ken Hurst]

I'm in agreement with Brian --- have been using the wifes self cleaning oven for years with success. Some actions/frames are tougher to anneal than others but are still cutable. To wit, the Colt SAA frames are all over the board --- some soften better than others due to different depths of CCH. The dis-coloration is nothing and usually a few swipes with 400 grit is all it takes. I once had a small furnace I bought from Brownells for annealing but sold it as I found the oven easier & cheaper to run. Always run oven at night when elec. rates or less .

HEY BRIAN, ARE YOU GOING TO MAKE THE GATHERING HERE IN MAY ?

 

[jerrywh]

The difference is, your not going to get the oxidization at 800° that you will at 1450° or 1500°. I am very interested in the titanium for a deoxidizing agent.
Great tip on the self cleaning oven.

 

[BrianPowley]

Aw Shucks, Ken. Your Engrave-in is May 2nd and I have a commitment on that weekend.
I'm deeply sorry I won't make it there.

 

[jimzim75]

I googled the subject of heat treating foil and titanium to see what was out there.
This brought up a couple of interesting things on heat treating.

http://www.keithcompany.com/Heat Treat Foil-668.asp
This is a good foil made of stainless with titanium added to mixture that is made for
heat treating.

The above site led to this site which I sure all knife makers know about but, it's new
to me. I'm quite happy in finding it, also.

http://jantzsupply.com/cartease/item-detail.cfm?ID=KF321

This site not only sells the foil but also the furnace and blades, parts or just about
anything connected with knife making. I would say they are reasonable in price.

Talk to ya later,
Jim

 

[joe seeley]

I use a large cast iron box that was made for pack hardening. I use my previosly used charcoal from pack hardening to pack the parts in. This will allow me to heat the parts enough for a full anneal without decarborizing the parts, and the charcoal is also an insulator that keeps the parts from cooling to fast. the next morning when I take them out of the oven they are still warm. This also helps keep warpage to a minimum when they are rehardend ( any parts that are going to be rehardend should go through a full anneal before being rehardend)

Joe

 

[Bill Burke]

the 800 - 850 degrees of the self cleaning oven is not enough heat for any kind of annealing to take place but is definately hot enough to temper most steel to a soft enough state that they can be cut easily. the tempered martinsite that you will get from a range is most likely a more desireable state for gun parts than the spherodized pearlite/cementite structure that the heat treating oven will yeild at higher temps. But the spherodized steel is the most easily machined structure.

I haven't read the links above but I do know that titanium absorbs oxegen very easily above about 900 degrees. I think that packing in the box of carbon is probably the cleanest but this method will definately increase the carbon level in the steel if heated above criticle.

Enco carries heat treating foil at a much better price than jantz or the knifemaking supply places but you have to buy a 50 or 100 foot roll www.use_enco.com thank you all for your acceptance and let me know if I can do anything or help in any way.

 

[ED DELORGE]

Hello Jim, It is good to chat with you again. Once about 30 years ago I had a luger to engrave for a customer. It was hard as glass. I called Jack Prudhome the engraver from north louisiana and asked his opinion. Jack said to put it in a kitchen over and heat the parts to 500 degrees. So I did. The parts were still very hard but engravable. My suggestion is to temper only to the degree that makes the part engraveable. So you might experiment, since you most likely don't know exactley what the carbon content is. Try it at 500 then if still not engraveable try 600 for an hour then let slowley cool. And so on. I once had to go up to 1250 on a colt single action cylinder before it was engraveable, only later to find out that the gun had been in a fire and quenched with the water hoses while still very hot. If I recall in the book "The 03 Springfiels" which gives a detailed step by step process for making every part of the rifle including anealing the parts after every maching step, it says they heated the parts to 800 degrees, before the next maching step. I have machined hundreds of 03 springfield and 98 mauser bolt shrouds to install a side safety that I used to manufacture. After 800 degrees in the oven these parts are still very tough to machine. 1400 degrees is getting very close to critical and easy to burn if not well protected with anti scale paint or nitrogen. While discussing annealing, My big question is has any one had any good experience anealing some of the stainless steel slides and cylinders?

Good luck, Ed

 

[jimzim75]

Hi Ed,
Good suggestion. I'm doing small test pieces to see what happens on the low end of the
scale. So the whole thing is a learning experience. Good to talk to you again.

Jim

 

[John B.]

Hi Jim,
It's my understanding that titanium in the wrap is designed to help with scale problems in the partial annealing of air hardening steels. Not for oil or water hardening steel.
If you check your post of the foil suppliers the first one indicates that it contains ti for use in annealing air hardening products.
I find a piece of paper in the wrap works well with O-1 or W-1.
The plain Enco foil work for me.
To borrow from Rex and Sam......your milage may vary.

 

[jerrywh]

I have been running experiments with a furnace I'm building and I found that the wrap works better with nothing in it at all. I tried titanium and paper. I also tried vacuuming all the oxygen out and back filling with argon. It seems to work as good or better by just wrapping it and sealing it well.

 

[jimzim75]

What I'm trying to naturalize in a rolling mold. This has a heavier cross section than a
gun part. Most gun part don't have heavy cross section, where as mine is nearly a
inch and half.

The light duty naturalizing process for gun part could be done at 500° F, I dought it would
make any impression on the rolling mold at all. So this means longer and higher temps.
To cut down on as much oxidation as possible. I'm going to wrap the part.

Next, I going to low ball the heating to 800° for the first try and see the results.
If it isn't soft enough to use carbides on then 1000° and up to 1200 if absolutely
necessary. I would prefer to simple leave the item longer at a lower temp.

This is a side project so I'm in no great rush to complete it. When I do, I'll pass on the
results.

Talk to ya later,
Jim

 

[david bain]

after the engraving is done,is the metal supposed to be rehardend.or do you send it off to be done