First timer here, would like some advice.

[WiseDuck]

Hello folks! I posted this on Reddit a couple of days ago and basically only got a handful of replies that told me to "send it in to someone" to have this part done. Basically, that wasn't helpful at all. If I can't do the most important part myself, I may as well not bother at all with this project. Anyways. Before the original post continues below, I'll give you a quick summary.... I work at a foundry, we have two huge ovens which are typically run at 1010°, 1020° or 1050° C. Sometimes higher when we pre-heat the ovens before putting in something large, the temp usually drops a lot when cold material is inserted. (In our case, suction roll jackets for the paper industry, from small to 60+ ton chunky bois) can piggyback on these whenever I want really, I just need to figure out if heat treating a knife at work is viable at all.

Original post:

So I've decided to make my own knife. I have bought all the materials needed and also have most of the tools I need, but the main problem is how to get the steel heat treated properly. There is a LOT of information out there and it's not always quite clear how it's done properly. Let's ignore everything else and focus on the two pieces of steel I have..
One is an X50crMoV15 stainless, which I believe is similar to what you'll find in many kitchen knives and it should also be reasonably similar to whatever Victorinox uses in their blades. I quickly realized that starting out with stainless was a bit of a mistake, but I mainly went with this because it is heat treated at EXACTLY the temps we typically run our ovens at, at work. I work at a foundry of sorts and we have huge ovens here which I should be able to use for this. I could just chuck the steel in a corner (these are ovens are fairly large, 6x4x2 meters or about 1350 cubic feet. And that's the smaller of the two) and let it sit in there for the required time. However, finding aluminum blocks to plate quench this thing properly is very difficult and expensive in Sweden. The website mentions this can be quenched in oil too, so maybe it's not all lost.

The other is a 1075 carbon steel, which is the one I will mainly focus on. Our ovens have sight-holes where I could easily poke the blade into while we are producing something else. I would be sticking these right into air temps of roughly 1050° C or 1922F. And I'd be keeping some warmed up oil on standby next to me. I intend to do a rough finish of the shape of the blade before this. But here is where things get a bit confusing...

After roughly finishing the blade, am I supposed to "normalize" it three times before the actual heat-treat plus quench? I.e. heat to non-magnetic, let it air cool, do this 3 times. Then heat to non-magnetic, let it go a shade or two past this, then quench in oil with a back and forth motion? Then check if a file skates across the blade or still takes off material. Another problem I have is that the workplace does not have a regular kitchen oven, is this where I can do a "snap temper" to at least prevent the blade from cracking, until I get home and temper it in my own oven? (Which would be several hours later, possibly the next morning) And if so, how is this done?

 

[Crag the Brewer]

When people think about maker's who send out for heat treat as not real maker's....... I like to bring up Bob Loveless.

Reddit was probably right, but I'm like you and I like to push things too. Good luck.



Let me ask.....?

Are You able to change, and control your temperatures at work?
Or are you stuck at that temperature because of the processes at work?

Focus on 1075 steel, heat it up to what you already know and quench it.

I wonder, would you be able to boil water at work?
Could a boiled water immersion temper work short term until you get home?
Then do real ones?idk? It's 3am and I'm on cold medicine.

 

[WiseDuck]

When people think about maker's who send out for heat treat as not real maker's....... I like to bring up Bob Loveless.

Reddit was probably right, but I'm like you and I like to push things too. Good luck.



Let me ask.....?

Are You able to change, and control your temperatures at work?
Or are you stuck at that temperature because of the processes at work?

Focus on 1075 steel, heat it up to what you already know and quench it.

I wonder, would you be able to boil water at work?
Could a boiled water immersion temper work short term until you get home?
Then do real ones?idk? It's 3am and I'm on cold medicine.

I have the equipment needed so not trying at all would be dumb imo. I want to feel that this is truly my handiwork from start to finish. Whether it's the right choice or not, that's another discussion. I could send it off. I could order a fully custom knife without doing any work at all. But where's the fun in that?

I am the oven operator so yes I have full control over the temp. But the ovens are very expensive to run so I can only piggyback when we are doing other things at the same time. Seeing as 1075 only needs to reach a certain temp once and not be held there, the oven temp shouldn't need to be changed. Unless heating up 1075 too fast is an issue?

All I know so far about 1075 is "a couple of shades past non-magnetic then dunk in 125f oil and move back and forth for 15s". That's it. I was hoping people had some more info about that process. The info I find online differs from place to place. It's very generalized and I'm still not sure about normalizing before quenching to get rid of shaping/grinding stresses.


I can boil water at work yes.

 

[Stacy E. Apelt - Bladesmith]

Welcome WiseDuck.

I'm going to tell you that your best choice is to send the blades to a proper HTer. They will do them right, at the right temperatures, and with the right equipment.

I suggest you use the custom search engine that is in the stickies to read up on HT and general knifemaking tasks. There is a lot of good info in these forums and in the stickys.

1075 is heat treated at 1475°F/800°C. Ideally it should soak for 5 to 10 minutes at that temperature. Your oven is much hotter than that and an attempt to stick it in and try to pull it out at the right temperature will almost surely fail. The edge will greatly overheat before the rest of the blade even gets close to hot enough.

Your stainless steel, X50crMoV15, is not a great choice unless you want a so-so knife. It won't get very hard (mid Rc50's) and does not hold an edge well. You are in Sweeden, so many good knife steels should be easily sourced. I suggest staying simple with a good stainless knife steel like RLW34 or AEB-L. These will work in your 1050°C oven. You would have to wrap the blade in a sealed stainless foil pouch to do HT. However, a pre-quench at 950°C is recommended, so that would not be possible. Aluminum plates are not an absolute necessity but help control warp. You can just take the blade packet out of the oven and let it cool to room temp hanging in the air.
Oil quenching absolutely requires the plates because warp is often increased by the oil quench.

 

[WiseDuck]

Welcome WiseDuck.

I'm going to tell you that your best choice is to send the blades to a proper HTer. They will do them right, at the right temperatures, and with the right equipment.

I suggest you use the custom search engine that is in the stickies to read up on HT and general knifemaking tasks. There is a lot of good info in these forums and in the stickys.

1075 is heat treated at 1475°F/800°C. Ideally it should soak for 5 to 10 minutes at that temperature. Your oven is much hotter than that and an attempt to stick it in and try to pull it out at the right temperature will almost surely fail. The edge will greatly overheat before the rest of the blade even gets close to hot enough.

Your stainless steel, X50crMoV15, is not a great choice unless you want a so-so knife. It won't get very hard (mid Rc50's) and does not hold an edge well. You are in Sweeden, so many good knife steels should be easily sourced. I suggest staying simple with a good stainless knife steel like RLW34 or AEB-L. These will work in your 1050°C oven. You would have to wrap the blade in a sealed stainless foil pouch to do HT. However, a pre-quench at 950°C is recommended, so that would not be possible. Aluminum plates are not an absolute necessity but help control warp. You can just take the blade packet out of the oven and let it cool to room temp hanging in the air.
Oil quenching absolutely requires the plates because warp is often increased by the oil quench.

Sticking it into an already hot oven is too much huh? I keep reading that soaking isn't required for 1075, 1084 or 1095. And now I hear it is required? Is it maybe possible to leave much of the tip not finished to increase its thickness and overall height to better even out the heat? We have some very large workpieces coming up over the next few weeks in the larger oven and the temps actually drop down to roughly 700-800° after we insert the workpieces. After that it can take up to an hour to get back to 1050° from whatever the temp drops down to. Within that window, would it be possible to at least give it a try with a soak? When the ovens are started in the morning, it can take this one about 2 hours to reach our set temp of 1050° which would also, possibly, present an opportunity to heat up the blade alongside the rest of the oven. We are having it relined right now and our new instructions will most likely include a much slower ramp-up than before, which could also be beneficial if I wanted to try carbon steels on it...

Ah so some stainless steels don't require more than to just be left hanging in the air to cool? That does greatly simplify things. I can find those steels locally, if they're better suited for the equipment I have available to me.

I have emailed a guy nearby that does a fair bit of forging, but I have yet to receive a reply. So I have no idea whether he can do this or not. Heat-treaters aren't very common in Sweden I'm afraid.

 

[WiseDuck]

Also. Can we take a step back here? Even a "so-so" knife would be an amazing start.

 

[Natlek]

I have the equipment needed so not trying at all would be dumb imo. I want to feel that this is truly my handiwork from start to finish. Whether it's the right choice or not, that's another discussion. I could send it off. I could order a fully custom knife without doing any work at all. But where's the fun in that?

I am the oven operator so yes I have full control over the temp. But the ovens are very expensive to run so I can only piggyback when we are doing other things at the same time. Seeing as 1075 only needs to reach a certain temp once and not be held there, the oven temp shouldn't need to be changed. Unless heating up 1075 too fast is an issue?

All I know so far about 1075 is "a couple of shades past non-magnetic then dunk in 125f oil and move back and forth for 15s". That's it. I was hoping people had some more info about that process. The info I find online differs from place to place. It's very generalized and I'm still not sure about normalizing before quenching to get rid of shaping/grinding stresses.


I can boil water at work yes.

Maybe you can HT that 1075 after you shoot down that oven .It is huge oven and I believe that it cool down very slow ? When temp. in oven drops to 800 Celisus insert your knife ? For tempering you can heat in oven some thick mild steel and use it to temper your knife observing the color in steel ?

 

[WiseDuck]

Welcome WiseDuck.

I'm going to tell you that your best choice is to send the blades to a proper HTer. They will do them right, at the right temperatures, and with the right equipment.

Edit: it's 120 bucks for a single heat treat... Uh I'll do it myself instead. Foe that cost I could try and fail to treat 12 pieces or so.


Well. I found a place that does this. I'll do this for the 1075 blade but will attempt to treat the x50 and other stainless steels at work since the temp is just right for it. I feel like I need the experimentation to learn. Just sending things off might be good for the results but you learn nothing from it.

 

[A.McPherson]

W WiseDuck have you tried looking up the local blacksmith society? I can bet there are blacksmiths around, they also will have the ovens/forges that will make all this much easier.

Blacksmiths trend to be very helpful people. I have yet to meet one who didn't want to talk about their craft, especially to someone who is interested in getting into the crafting of metal objects...

www.konstsmidesforeningen.se
www.nhjsgille.com

Here are two that I found with a quick Google search...

 

[WiseDuck]

W WiseDuck have you tried looking up the local blacksmith society? I can bet there are blacksmiths around, they also will have the ovens/forges that will make all this much easier.

Blacksmiths trend to be very helpful people. I have yet to meet one who didn't want to talk about their craft, especially to someone who is interested in getting into the crafting of metal objects...

www.konstsmidesforeningen.se
www.nhjsgille.com

Here are two that I found with a quick Google search...

I have emailed a guy that does this kind of stuff less than 10 mins from where I live. No reply so far but I'll give it some time. I've also sent emails to 3 others. I still intend to give this a try with stainless steels that work with the oven Temps at work and possibly my 1075 if the smith's nearby won't do it. Most of them appear to focus mostly on traditional smiting. I.e. banging stuff into shape. I'll see what they have to say tomorrow.

 

[WiseDuck]

Maybe you can HT that 1075 after you shoot down that oven .It is huge oven and I believe that it cool down very slow ? When temp. in oven drops to 800 Celisus insert your knife ? For tempering you can heat in oven some thick mild steel and use it to temper your knife observing the color in steel ?

It does indeed cool down and heat up slowly. This could be an option but the heat is very difficult to control. We do anneal workpieces overnight for customers and other parts of this industrial site. Altho this is typically done at the very very end of shifts.

 

[Stuart Davenport Knives]

I say try it! Yes, that X50Cr steel is basically the same thing used in Victorinox and other companies. It's not my cup of tea, much preferring AEBL/13c26 or CPM154, but here in the states I think you could probably go to just about any butcher's shop and ask them what knives they use all day, every day and they'll tell you Victorinox or some other brand that uses X50Cr or 1.4116. They prefer the ease of touch up vs overall edge retention. I prefer edge retention, but I'm no professional butcher.

Not sure what Stacy was getting at, but yes you want the oven at temp prior to inserting the knife, for any steel. As long as the oven reaches temp and has settled at that temp for a while, then insert the blade and begin a 20 minute soak. His concern was overheating, but if the oven has reached temp and settled there for a while (I wait about 20 minutes with my oven) I think you are good. You know your oven better than I do. Keep the blade away from the heating elements. But you will need some sort of decarb protection. I didn't read everything you mentioned, but if the oven has like an argon gas purge, you're good. Otherwise you'll need stainless steel foil to protect the blade.

It doesn't have to be aluminum quench plates. If you have thick flat steel laying around, use that for your first jump into things. Like Stacy mentioned, most stainless steels (if not all) will harden in still air, but the plates help keep it straight. If you keep making knives, eventually you'll want to use aluminum plates. I also used compressed air between the plates when quenching, but not really necessary.

Depending on the prior condition of 1075, you don't need to normalize it or thermal cycle. If you are forging, of course you will need to normalize it. If you bought it from a knife supply store, it's most likely annealed already, and so you just need to harden it. 1075 when forged does not really need a soak at hardening temp. However, if the 1075 is from a knife supplier in the annealed state, yes, give it a 10 minute soak. The carbon is tied up in carbide and needs that soak to go into solution. When forged, the steel is no longer annealed (unless you do an anneal after the normalizing), and the carbon is ready to be put in solution, so no soak is needed, really. Quench in fast oil like Parks 50 or even canola oil preheated to ~130°F will work decently, as long as the blade isn't too thick, and preferably some grinding has been done previously so the edge is thinner. 1075 is good for hamons, so if you have some refractory cement handy, you can clay coat and shoot for a hamon.

Have fun, good luck, and be safe!

 

[WiseDuck]

I say try it! Yes, that X50Cr steel is basically the same thing used in Victorinox and other companies. It's not my cup of tea, much preferring AEBL/13c26 or CPM154, but here in the states I think you could probably go to just about any butcher's shop and ask them what knives they use all day, every day and they'll tell you Victorinox or some other brand that uses X50Cr or 1.4116. They prefer the ease of touch up vs overall edge retention. I prefer edge retention, but I'm no professional butcher.

Not sure what Stacy was getting at, but yes you want the oven at temp prior to inserting the knife, for any steel. As long as the oven reaches temp and has settled at that temp for a while, then insert the blade and begin a 20 minute soak. His concern was overheating, but if the oven has reached temp and settled there for a while (I wait about 20 minutes with my oven) I think you are good. You know your oven better than I do. Keep the blade away from the heating elements. But you will need some sort of decarb protection. I didn't read everything you mentioned, but if the oven has like an argon gas purge, you're good. Otherwise you'll need stainless steel foil to protect the blade.

It doesn't have to be aluminum quench plates. If you have thick flat steel laying around, use that for your first jump into things. Like Stacy mentioned, most stainless steels (if not all) will harden in still air, but the plates help keep it straight. If you keep making knives, eventually you'll want to use aluminum plates. I also used compressed air between the plates when quenching, but not really necessary.

Depending on the prior condition of 1075, you don't need to normalize it or thermal cycle. If you are forging, of course you will need to normalize it. If you bought it from a knife supply store, it's most likely annealed already, and so you just need to harden it. 1075 when forged does not really need a soak at hardening temp. However, if the 1075 is from a knife supplier in the annealed state, yes, give it a 10 minute soak. The carbon is tied up in carbide and needs that soak to go into solution. When forged, the steel is no longer annealed (unless you do an anneal after the normalizing), and the carbon is ready to be put in solution, so no soak is needed, really. Quench in fast oil like Parks 50 or even canola oil preheated to ~130°F will work decently, as long as the blade isn't too thick, and preferably some grinding has been done previously so the edge is thinner. 1075 is good for hamons, so if you have some refractory cement handy, you can clay coat and shoot for a hamon.

Have fun, good luck, and be safe!

Thank you, that's the encouragement I needed! I'm very much used to lower-end steels and have gotten quite good at quickly sharpening up these when they dull. I don't very much mind it, I'm not a nerd in that regard even tho I do own some 154CM and S30V blades. Knife use in Sweden is mainly something for work or for some simple wood splitting, whittling and food prep when out camping or hiking. I "EDC" a Victorinox Minichamp but that's it. About the soak time, say the oven is at 1050C, the website I bought the steel at calls for a soak of 5 mins or so at that temp, then temper at 160C for 1 hour, twice. So which is it, would you say? I'll buy some stainless foil to wrap up the knife with before doing this. As for steel blocks, we have plenty of those laying around that can be used for a quench that keeps the blade straight. Compressed air connections are everywhere here, so that's not a problem either. Aluminium plates are sadly very difficult to find in Sweden, at least of the thickness I've seen on Youtube. If you're a machinist at a big company, then maybe, yes, but as a regular person... No, eBay maybe, locally? Nope. I spent some time on the X50 today and got the basic shape ready, now I need to work on bevels and such and also order the stainless foil required to avoid excessive decarb.

The 1075 has been "soft annealed" for ease of machining/forming. I find your reply a bit confusing. My aim is to do 90% of the shaping prior to hardening, so if it's soft annealed all I need to do is bring it up to critical temperature, dunk in oil and that's it? Or would you say a soak is required? 800C is sadly too low for our ovens to maintain. They're quite archaic in that regard. They burn oil similar to diesel and are controlled by a PLC hooked up to temp sensors in 4 different spots. They were very much made for a specific purpose, to soak stainless specialty steels (ranging from 40mm to 130mm in thickness) for several hours at a time at very high temps before these are shaped into pipes and such.

 

[Lorien]

Edit: it's 120 bucks for a single heat treat... Uh I'll do it myself instead. Foe that cost I could try and fail to treat 12 pieces or so.


Well. I found a place that does this. I'll do this for the 1075 blade but will attempt to treat the x50 and other stainless steels at work since the temp is just right for it. I feel like I need the experimentation to learn. Just sending things off might be good for the results but you learn nothing from it.

well, maybe. Learning how to make a good knife is extremely time consuming- especially the first times- and hard enough as it is. It sucks to render all that hard work to your first knives only to make them terrible with a bad heat treatment. Part of the satisfaction of making your first knives is being able to use them, but no matter how good a job to do with the making them part, if they aren't hard enough, have chunky grains, stress fractures etc then...well, I know I wouldn't like it.

with heat treatment, 'roughly the right temperature' is a huge crap shoot. It doesn't sound to me like those huge ovens will give you any predictability.

anyway, I'm not one to tell anyone what to do, so take my input for what it's worth. Just a suggestion.

 

[WiseDuck]

well, maybe. Learning how to make a good knife is extremely time consuming- especially the first times- and hard enough as it is. It sucks to render all that hard work to your first knives only to make them terrible with a bad heat treatment. Part of the satisfaction of making your first knives is being able to use them, but no matter how good a job to do with the making them part, if they aren't hard enough, have chunky grains, stress fractures etc then...well, I know I wouldn't like it.

with heat treatment, 'roughly the right temperature' is a huge crap shoot. It doesn't sound to me like those huge ovens will give you any predictability.

anyway, I'm not one to tell anyone what to do, so take my input for what it's worth. Just a suggestion.

I'm waiting on some smiths to get back to me regarding a paid HT. So I'm keeping that door open. As for the oven temps, they can be fairly stable but the size of these ovens makes it impossible to be as precise as the small kilns used by knifemakers. The small oven will undergo some maintenance over the next two weeks and be unavailable, after that it should be a lot more stable. The big oven we're forced to use for everything in the meantime, is actually manually controlled on a per-burner basis. Altho the temp display of each burner is digital, so if you keep a close eye on it... So in this particular oven, the only way of doing it is to stick a piece of steel inside and check the state of the steel often with a magnet to see if its reached critical. I have to wait for maintenance to finish on the other one to even attempt anything stainless.

 

[WiseDuck]

I say try it!

-snip-

Have fun, good luck, and be safe!

Oh, one more thing. Say all of this experimentation doesn't pan out and the ovens at work aren't quite suitable for this. Do you have any opinions on the Devil Forge with dual burners? I just bumped into these on Amazon and judging by some Youtube videos, these seem suitable for hardening carbon steels? The price almost seems to good to be true, honestly.

 

[Blankblank]

At the temp the oven is at. I imagine you could likely get by just heat treating the 1075 just like it was a forge.

So preferably start from an pearlitic state, or even do something like a triple quench. Basically going doing the austenizing and quenching multiple times. I think could lead to decent results

Martensite converts to austenite pretty rapidly, and pearlite is the next slowest behind that. Going from spherodized steel would be the slowest. So what you want for your method. Is going to be having the steel in a state that needs little to no soak time.

So i recommend heating to nonmagnetic, then either quenching or air cooling. Then doing that again, at least once. You're going to likely need to moved the blade around some, and maybe take it in and out to make sure it heats evenly. That part you will need to figure out yourself.

As far as doing this in the future. Others recommendations for aebl, and other higher alloyed steels are definitely a better choice. But there is no reason doing the 1075 isnt going to be possible. Just know, its easy to mess up, and likely wont be as good as if you had done it in an oven at the exact temp you need.

 

[Ken H>]

I'm waiting on some smiths to get back to me regarding a paid HT.

Providing you're in the USA I'd strongly recommend www.jarodtodd.com for HT'ing

 

[weo]

I have emailed a guy that does this kind of stuff less than 10 mins from where I live. No reply so far but I'll give it some time.

If you don't hear back in a couple days, I'll suggest dropping by with a note or the post office. Not sure how old the smiths are that you're talking about, but in my experience, many smiths over 40 are not as "plugged in" as youngsters, and often don't even open e-mails from random folks and your note might have gone directly to their spam folder. It might not hurt to have a six-pack of beer with you when you drop by....

 

[HSC ///]

I believe jürgen schanz will be much less costly for you for a HT in the EU
or ask S Scaniaman
if you run out of options, I'm in France and I will do it for you, you pay for the shipping back and forth.

aluminum quench plates you can get form ebay coming from Poland, that's where I got mine.

btw in my past, I worked 12 yrs at a investment foundry,