I guess my question is, do you not anneal your blades prior to profiling/rough grinding? Most grinding/metal removal, as well as holes being drilled is done with the steel annealed.

One of the reasons that I choose to do a lot of differential heat treating is because it allows me to harden those areas I want to, and leave those areas I wish to in a softer state that allows for filing, drilling, etc. On nearly all the blades that I differentially heat treat, I drill all the holes, and other cutting operations after the blades are heat treated. While some choose to fully harden, then attempt to soften specific areas (which doesn't always work), I simply choose not to harden the areas I wish to remain in a softer/tougher state..... in my mind's eye, why harden, then try to soften.....that's just adding another step that might or might now work.

Personally, my methodology includes the following:

1. Forge the Blade to shape

2. Three thermal cycles (bring the blade(s) to no more then 1350F and allow to cool in still air to 900F or less)

3. Heat to just critical temp and place in a container of vermiculite overnight to anneal

4. Remove forge scale (I use a 7" angle grinder)

5. Profile and rough grind (if the blade is to be fully hardened/heat treated, all holes are drilled, and any other operation that I can't accomplished when the blade is fully hardened) (If the blade(s) are destined for differential heat treating, then all the holes, etc. are done post heat treat)

6. Harden

7. Temper

8. Finish grind

9. Final/Hand finishing

10. Guard/bolsters/handle/frame, or whatever else I want to do in order to assemble/complete the knife.

11. Final sharpening is never done until the blade is either sold, and ready to go out the door for delivery, or right before it goes in the carry case bound for a knife show.

Hope that helps!

My first forged knife came after the Batson Symposium weekend, until then I had only done stock removal, so I was confused on anneal part and your order or assembly makes it very clear.

"1. Forge the Blade to shape

2. Three thermal cycles (bring the blade(s) to no more then 1350F and allow to cool in still air to 900F or less)

3. Heat to just critical temp and place in a container of vermiculite overnight to anneal"

Ive not looking into re-sizing photos yet, but this is exactly what i was needing. Im assuming its work hardening that i am not used to. I will also need to look into vericulite. I have heard others talking about annealing files and such, but had never needed to in the past. Thank you for your help, I was concerned I had made critical error.

Normalizing seems to be an issue for me as well. I just returned from garage where I heated O1 toolsteel through what I thought was 3 normalizing temps breakign off a 1 inch piece each time. The grain structure still looks shiney and sugary to me, so im concerned I am not normaling it correctly.

I heat it to non magnetic, then im pulling it out, air cooling about 5 minutes, then snapping it off. Is my problem that its O1 and i am not allowing time to soak at 1500ish degrees?

Everyone has sonewhat different methods Anthony. My normal sequence is forge the knife, then normalize, first thermal cycle bring the blade to 1600 degrees air cool to black, then back for the second cycle at 1500 air cool to black, then the third cycle is at 1250 and into vermiculite or lime. The third cycle is the anneal. I just noticed you said O1. O1 is an alloy tool steel and can present problems. It forges well, but you definitely have to get the thermal cycling and annealing down. It will also require a soak for quenching. Good steel but it requires some extra care. I would suggest 5160 or 1084 steel.

Brion

Thank you for your assistance Brion, the O1 toolsteel was the metal I was using because I was led to believe it was a forgiving steel (like 1084 is supposed to be). I actually have a piece of that from Aldo in garage now and will be using this exclusively until I am comfortable with processes. Aldo gave me quite a stern talking to over the O1.

Today my 30 PSI gauge and regulator came in, so I set that up. Also purchased a digital thermometer, but had to order the high K type prong and should be here Tuesday. Im hoping by seeing my temps, i can better understand control of the heat. for the vermiculite, can I simply bury it in the bucket, or do I need to place other hot bars in there? Sorry for so many questions, this annealing stage will fix my pending issues.

Thanks,

Tony DeLalla

You have great help given above. As for the vermiculite, you can get some from Home Depot or wherever sells gardening supply stuff. I put mine in a metal trash can, but you could put it into whatever container you've got. All you're doing is putting the hot blade in something that is very insulating, which will cause it to cool very slowly. That's what ends up annealing the steel. So, you don't need to put another hot piece of steel in the vermiculite, just whatever you're working on. One word of caution about your container though...I suggest metal. If you use something flammable and the vermiculite is holding a lot of heat for a long time....imagine the bad things that can happen there...

Good luck, you're definite going to prefer working on those blades more when they're softer <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//smile.gi f' class='bbc_emoticon' alt=':)' />.

Jeremy

Great help and this is what im looking for. I like the idea of annealing after the normalizing cycles and will get that step added in. Thank you all for the guidance.

Your steel choice will make all the difference in the choices made. Simple carbon steel will give you much more latitude in simply normalizing, alloying will increase the need for annealing. From all of my experience, from HRC, tensile, Charpy impact, metallographic observations, and heavy field testing, tempered martensite gives the best strength to toughness yield of any steel phase, and homogeneity is the key to maximizing properties. Thus I harden everything that I want the best properties from, and then adjust the hardness to toughness ratio accordingly, which is easily done with zone tempering. But a huge consideration is how things will soften and what form the phases created in softening will take. Pearlitic steel will have carbide sheets that will make drilling miserable no matter what you do until those sheets are broken up by dissolving and redistributing. Simply tempering these sheets will do nothing, unless you go high enough to form spheroidal cementite which will then be in concentrated clusters following the pattern of the original sheets, which will still be a problem. But if the solution was homogenous in the martensite formation the carbide precipitation will also be uniform and thus eliminate the clustering effects. Such martensite after deep tempering should drill much better than pearlitic steel that was never hardened. In fact, when I encounter a spot that squeaks and dulls my drills, the best remedy I have found is to heat the spot high enough to dissolve everything, cool quickly enough to avoid any large carbide formations (this can be air but may even include quenching), and then drawing the area back to soft with high temperature temper.

Picked up lime (pellets) not sure if that will work. I did not see the vermiculite so I went with the lime pellets. Also grabbed a metal pail with lid.

Ill give it a shot tonight and hopefully be back in business with a new step added! Thank you Kevin for your input. The more I learn of the composition and transitions, the more these sheets and clusters will make sense to me. Im still in the "not sure what temp my metal is phase" of this adventure. Though my prong to the thermometer will b here Tuesday to remedy that, or to get me closer to knowing that assuming forge temp is in line with metal temp determination.

Try to find vermiculite. Lime, especially in pellet form won't insulate enough to force the slow cooling needed.

|quoted:

Try to find vermiculite. Lime, especially in pellet form won't insulate enough to force the slow cooling needed.

bah - was hoping someone would confirm or deny this while im at work and able to go to another store(thanks for the comment). I still have time to try a different store then. Vermiculite pellets okay if that's all I find? I got lime at home depot, so ill try lowes.

edit: Horticulture vermiculite x2. mission accomplished.

|quoted:

bah - was hoping someone would confirm or deny this while im at work and able to go to another store(thanks for the comment). I still have time to try a different store then. Vermiculite pellets okay if that's all I find? I got lime at home depot, so ill try lowes.

edit: Horticulture vermiculite x2. mission accomplished.

Hold on. I didn't have time to read the whole thread this morning as I was leaving to teach a handles and guards class at the ABS school in Troy OH. I am here now and have time in my hotel to read everything. My initial input was about soft/hard areas of blades, but now, if I read it correctly, I see you are working with O-1. I have been using this alloy most of my career and have a pretty good understanding of it. Often if Aldo gives somebody a good talking to about an alloy it is because Aldo has already been talked to by me. If it is O-1 the vermiculite will do nothing at all for you and and may even be bad for the final product.

O-1, having .9% carbon will not only suffer from the slow cool in vermiculite from above critical (heavy carbide aggregates and even the possibility of grain boundary carbide networks, which would be very bad) it would also laugh at annealing this way due to the alloying present. Lamellar style annealing is right out with O-1, the only hope of annealing is in spheroidizing methods.

Ditch the vermiculite and follow your normalizing with several cycles at 1300F (but no higher) with air cools, or a soak at 1275F for 30-60 minutes followed by a slow cool. This will produce fine spheroidal carbides in a primarily ferritic matrix (the softest condition you can get, and ideal for machining and cutting).

O-1 is only a beginner, or easy, steel in sense of what it takes to quench it, everything else about it makes it more for shops that have very good control over heating methods.

Due to the eutectoid nature of 1084, most of these considerations can be replaced with simple normalizing operations.

I had these sitting in vermiculite overnight, then read this Kevin. When I get home form work, ill pull them out and throw in scrap pile. I dont have temperature control on my forge when I made these and im sure I burned the grain knowing the little i know now. This week, Ill add the thermometer and start the focus on temperatures. I have a full bar of 1084 Ill get started with. Scrapping the o1 will be better than trying to put out bad product. Was good practice and with the 1084, Ill add the annealing phase. This dry run has me set up for that now and you all have given me a good chunk of information to incorporate.

Thank you,

Tony DeLalla

ok - the 01 did anneal enough to drill pin holes, but as kevin said, it is still fairly hard. Thats good experiment and a lesson learned. I know have the vermiculite in the canister and tomorrows 1084 knifes will fit nicely in there. I really appreciate all of your guidance on this. The metal canister did get hot on the side so that was good to know up front.

Next challenge for me is not burning the metal...

|quoted:

ok - the 01 did anneal enough to drill pin holes, but as kevin said, it is still fairly hard. Thats good experiment and a lesson learned. I know have the vermiculite in the canister and tomorrows 1084 knifes will fit nicely in there. I really appreciate all of your guidance on this. The metal canister did get hot on the side so that was good to know up front.

Next challenge for me is not burning the metal...

Anthony, no need to scrap the O-1 knives, there is nothing that has been done that can't be undone thus far. Now your burning issue is another matter...