How To First knife heat treating

[TotallyAutistic]

I am currently working on my first knife which is a pushknife (I know I should've picked an easier knife to begin with but I've gotten quite far on it) and I'm wondering about what I should do to heat treat it.
I have zero to little knowledge on what exactly happens when heat treating so please bear in mind I am not a professional.
I don't know any methods other then heating the steel until a magnet won't stick to it anymore and after that dunk it in some warm oil and move it around a bit. I know it gets hard and brittle, but after 2 hours in the oven at 250 degrees C the stress is out of the steel and really durable. That's about the only thing I know about heat treating.

Any tips for this blade or heat treating in general are really appreciated!

 

[Hubert S.]

Welcome to the forum. What you describe sounds reasonable. The tempering temperature seems a bit high to me, but that depends on the type of steel you use and the hardness you want to achieve. I always use two tempering cycles. You might get better answers if you provide the steel type.

Check the Dutch knife laws, I think push daggers are illegal in the Netherlands.

 

[Londinium Armoury]

I am currently working on my first knife which is a pushknife (I know I should've picked an easier knife to begin with but I've gotten quite far on it) and I'm wondering about what I should do to heat treat it.
I have zero to little knowledge on what exactly happens when heat treating so please bear in mind I am not a professional.
I don't know any methods other then heating the steel until a magnet won't stick to it anymore and after that dunk it in some warm oil and move it around a bit. I know it gets hard and brittle, but after 2 hours in the oven at 250 degrees C the stress is out of the steel and really durable. That's about the only thing I know about heat treating.

Any tips for this blade or heat treating in general are really appreciated!

I think generally speaking with most basic steels Hubert is probably right about 250C being a little on the high side, you might want to crank it down a notch. That's going to be over 480F, but it depends on your steel, some steels require hotter than that for tempering, but those are usually HSS type steels that have lots of Cobalt and Tungsten in them.

I normally aim for around 200C which is around 390F but that is on the harder side than most people shoot for, the lower you temper it the higher the HRC will be, but it will also lower it's toughness and springy properties. Most knife makers aim for a light straw colour after tempering basic steels, and in the range of 210 C - 230 C But some go lower and some go higher I guess.

I'd generally avoid moving the blade around during the quench, in my experience it's always lead to warping, if you are going to move it around do gentle up and down cutting strokes, never side to side or you will get a wavy blade. I have had best results quenching in a big container, one where you dont risk knocking the blade on the walls, and I'm not sure if the science is solid behind my method (it might be though) but I think quenching in a big container gives better results, with lots of liquid inside it. I don't like quenching in small paint cans or tiny quenching tubes, because the liquid absorbs all of the heat and gets too hot, slowing the cooling rate down. I find when I quench in a huge bath or tank I get better results. I could be wrong though a small quenching tube could be perfectly fine I see lots of guys using them, but I always go for a huge wide quenching container. I also do not move my blade only move downwards, and sometimes do interupted quenches by leaving it in for a few seconds, removing it then putting it back in a fresh spot.

 

[TotallyAutistic]

Welcome to the forum. What you describe sounds reasonable. The tempering temperature seems a bit high to me, but that depends on the type of steel you use and the hardness you want to achieve. I always use two tempering cycles. You might get better answers if you provide the steel type.

Check the Dutch knife laws, I think push daggers are illegal in the Netherlands.

Thanks for the reply
I am using 1095 steel and I wouldn't really know what type of hardness I want to achieve, just hard enough I guess haha

 

[TotallyAutistic]

I think generally speaking with most basic steels Hubert is probably right about 250C being a little on the high side, you might want to crank it down a notch. That's going to be over 480F, but it depends on your steel, some steels require hotter than that for tempering, but those are usually HSS type steels that have lots of Cobalt and Tungsten in them.

I normally aim for around 200C which is around 390F but that is on the harder side than most people shoot for, the lower you temper it the higher the HRC will be, but it will also lower it's toughness and springy properties. Most knife makers aim for a light straw colour after tempering basic steels, and in the range of 210 C - 230 C But some go lower and some go higher I guess.

I'd generally avoid moving the blade around during the quench, in my experience it's always lead to warping, if you are going to move it around do gentle up and down cutting strokes, never side to side or you will get a wavy blade. I have had best results quenching in a big container, one where you dont risk knocking the blade on the walls, and I'm not sure if the science is solid behind my method (it might be though) but I think quenching in a big container gives better results, with lots of liquid inside it. I don't like quenching in small paint cans or tiny quenching tubes, because the liquid absorbs all of the heat and gets too hot, slowing the cooling rate down. I find when I quench in a huge bath or tank I get better results. I could be wrong though a small quenching tube could be perfectly fine I see lots of guys using them, but I always go for a huge wide quenching container. I also do not move my blade only move downwards, and sometimes do interupted quenches by leaving it in for a few seconds, removing it then putting it back in a fresh spot.

Thanks for the reply
If I make a little instruction from what you've wrote: I will crank down the tempering temperature to 220C and won't move the blade when quenching. Correct? I could send a picture of what the blade looks like if you want

 

[TotallyAutistic]

Welcome to the forum. What you describe sounds reasonable. The tempering temperature seems a bit high to me, but that depends on the type of steel you use and the hardness you want to achieve. I always use two tempering cycles. You might get better answers if you provide the steel type.

Check the Dutch knife laws, I think push daggers are illegal in the Netherlands.

Also, I've seen the Dutch knife laws and know the pushknife is illegal, but I will not take it out the shop and is purely for crafting experience.

 

[Londinium Armoury]

Thanks for the reply
If I make a little instruction from what you've wrote: I will crank down the tempering temperature to 220C and won't move the blade when quenching. Correct? I could send a picture of what the blade looks like if you want

Sure I would like to see pictures, I think if you tell us what blade steel you are using it would help more with the temp degree advice, 220C sounds fine to me for most basic carbon steels. If you are quenching in a larger bath or container I don't think moving the blade around is needed, leave enough volume so you can move it downwards slowly. But I tend to follow more Japanese quenching methods so I might be bias there. If you use a smaller quenching bath or pot then you might need to agitate the blade a little up and down (Never side to side) People do this to stop a vapour jacket fully forming around the blade, and to bring fresh liquid in contact with the blade. Just don't move it fast or jam it into the bottom or side of the container if you do agitate it. I haven't had bad results from not agitating, I seem to get less warps than people who do move the blade around.

 

[A.McPherson]

Hi, welcome to the forum!

For all your heat treating knowledge.
https://knifesteelnerds.com/categories/

Also there are "sticky" posts on the top of the main makers page, read them. They will also answer lots of your questions.

Use this search engine to search for your topics:. https://cse.google.com/cse/publicurl?cx=012217165931761871935:iqyc7cbzhci

 

[scott kozub]

here's a link to Alpha knife supply's 1095 page. The heat treat info is on the bottom of the page.

https://www.alphaknifesupply.com/shop/1095-carbon-steel

My suggestion would be to aim for a fairly hard blade say around 63HRC. Don't mount a handle and put a quick and dirty edge on it. Do the brass rod test (

) and see if its chippy. (Stay away from more abusive testing until you drop the hardness). If it is chippy, you can make a little more obtuse of an edge, widen TBE or temper it back by raising the temper temp a bit using the chart in the alpha link as a guide. You can temper as much as you want. You'll learn a ton from this and gauge what edge geometry work well with what hardness. You'll probably want around 60HRC or so.

This is your fist knife so use it as a learning experience. Don't be in a rush (really hard to do with first few knives) and remember that you don't need a expensive tools to make a high quality knife. Just skill, and attention to detail.

 

[TotallyAutistic]

Sure I would like to see pictures, I think if you tell us what blade steel you are using it would help more with the temp degree advice, 220C sounds fine to me for most basic carbon steels. If you are quenching in a larger bath or container I don't think moving the blade around is needed, leave enough volume so you can move it downwards slowly. But I tend to follow more Japanese quenching methods so I might be bias there. If you use a smaller quenching bath or pot then you might need to agitate the blade a little up and down (Never side to side) People do this to stop a vapour jacket fully forming around the blade, and to bring fresh liquid in contact with the blade. Just don't move it fast or jam it into the bottom or side of the container if you do agitate it. I haven't had bad results from not agitating, I seem to get less warps than people who do move the blade around.

https://imgur.com/a/x1eb7GB picture of first knife. The holes aren't equal because the punch I made on the left side was smaller than the rightside punch. It's also not the most symmetric blade but for a first knife + 2 sides freehand grind I think I did pretty well. The part where your fingers are wrapped around aren't equal aswel, but that's not a major issue. Also the part where the thin part starts becoming the thick part isn't equal aswel.. Alot of inequality but not the worst haha
The steel I'm using is 1095 steel

 

[Richard338]

I have several suggestions:
1) draw your pattern, either on paper or with a computer, ensuring symmetry.
You can draw free-hand if you prefer (on one side), but then fold the paper over to make the other side match.
2) Make a cardboard version before cutting any steel.
Here you can make sure that the sides of the handle are wide enough (not obvious here), the knuckle clearance is enough, and the stem is thin enough to pass comfortably between the fingers.
3) trace your pattern onto steel.
4) use a punch to solidly mark where you plan to drill holes, then use a drill press, with your work piece firmly clamped (your hole shows that the bit drifted...)
Do this before profiling, while the steel is larger and easy to clamp.
5) Carefully grind, file etc the profile to shape. This is is easiest step in the process, so get it right.
6) Grind or file the bevels. Yours are rounded over. Make sure to hold a consistent angle and try for a crisp transition from the bevel to the flat.

 

[Londinium Armoury]

https://imgur.com/a/x1eb7GB picture of first knife. The holes aren't equal because the punch I made on the left side was smaller than the rightside punch. It's also not the most symmetric blade but for a first knife + 2 sides freehand grind I think I did pretty well. The part where your fingers are wrapped around aren't equal aswel, but that's not a major issue. Also the part where the thin part starts becoming the thick part isn't equal aswel.. Alot of inequality but not the worst haha
The steel I'm using is 1095 steel

You can fix all of those mistakes, and if you have a round file you can clean all of it up with hand filing. There is a way to fix the off center holes as well. Just leave those 2 holes as epoxy catchers. and drill 2 new holes more to the center of the piece. Mark them out with a sharpie or punch them. You can still get that piece symmetrical it's not beyond saving, you can clean those bevels up as well with a hand file by draw filing it clamped hanging off a bench. You won't see those holes under the handle scales so nobody will know they are there and they will help the epoxy, most knives have hidden drill holes under the scales it helps make a stronger handle constuction, all of my knives have random drill holes under the handle scales. Just drill 2 new holes but mark them out and measure up first before drilling.

 

[TotallyAutistic]

You can fix all of those mistakes, and if you have a round file you can clean all of it up with hand filing. There is a way to fix the off center holes as well. Just leave those 2 holes as epoxy catchers. and drill 2 new holes more to the center of the piece. Mark them out with a sharpie or punch them. You can still get that piece symmetrical it's not beyond saving, you can clean those bevels up as well with a hand file by draw filing it clamped hanging off a bench. You won't see those holes under the handle scales so nobody will know they are there and they will help the epoxy, most knives have hidden drill holes under the scales it helps make a stronger handle constuction, all of my knives have random drill holes under the handle scales. Just drill 2 new holes but mark them out and measure up first before drilling.

Thank you, very helpful tips
I do have a little round file and tried to make them symmetrical again with that, but it took very long so maybe the file is just worn. I'll try again if it doesnt'work well I'll get a new one
Talking about epoxy, what epoxy should I use for this? I'm adding a small wooden handle on the bottom but don't know what epoxy to use. Seen people on youtube use different epoxy at the same time and didn't look into it yet so you probably know more about it then I do haha

 

[Londinium Armoury]

Thank you, very helpful tips
I do have a little round file and tried to make them symmetrical again with that, but it took very long so maybe the file is just worn. I'll try again if it doesnt'work well I'll get a new one
Talking about epoxy, what epoxy should I use for this? I'm adding a small wooden handle on the bottom but don't know what epoxy to use. Seen people on youtube use different epoxy at the same time and didn't look into it yet so you probably know more about it then I do haha

No problem, most of the pros use Acraglas or west Gflex as far as i'm aware, i've always used gorilla glue epoxy personally. I tend to just avoid the fast 5 min stuff, a good 12-24 hour cure time 2 part epoxy will be fine. I use gorilla glue because I can unclamp it after 20 mins curing and finish the handle off without waiting, then let it cure after, just because i'm impatient and don't like not being able to work on the project while it sets. I haven't had good results with the clear gorilla glue though, it looks nicer but I don't think it's as strong as the nasty yellow stuff. They make a dedicated epoxy as well.

 

[weo]

Also, I've seen the Dutch knife laws and know the push knife is illegal, but I will not take it out the shop and is purely for crafting experience.

Although it's too late, I'll throw this out for you to think about in the future. Just because you have no intention on using it, you can't be sure what happens to it forever in the future. And now that you've posted this on the internet, it's out there for the authorities in the event that it gets stolen and someone else uses it. You've admitted that you know the laws and are ignoring them. Not the best idea. I don't know the legal system in the Netherlands, but if you were here in the states, the combination of a smart and aggressive DA and a judge who looks purely at the letter of the law could be enough to get you in trouble. Hopefully this won't come back to bite you in the future.

 

[scott kozub]

You can fix all of those mistakes, and if you have a round file you can clean all of it up with hand filing. There is a way to fix the off center holes as well. Just leave those 2 holes as epoxy catchers. and drill 2 new holes more to the center of the piece. Mark them out with a sharpie or punch them. You can still get that piece symmetrical it's not beyond saving, you can clean those bevels up as well with a hand file by draw filing it clamped hanging off a bench. You won't see those holes under the handle scales so nobody will know they are there and they will help the epoxy, most knives have hidden drill holes under the scales it helps make a stronger handle constuction, all of my knives have random drill holes under the handle scales. Just drill 2 new holes but mark them out and measure up first before drilling.

I agree with this. For a first knife you actually picked a bit of a difficult design but as it isn't heat treated you can easily file a bit here and there to get things symmetrical. The holes are the biggest issue. If you're putting a handle on you can enlarge them to insure the pins are aligned.

Another tip for symmetry is to draw a straight line on paper and only sketch out 1/2 the blade. Fold along the line and cut out the paper. Each side will be the same. Then transfer that to cardboard, plywood or steel.

 

[weo]

most knives have hidden drill holes under the scales it helps make a stronger handle constuction,

While a lot of makers use this line of thinking as a reason for drilling holes, it is not correct. The reason to drill holes is to reduce the weight of the blade and/or change the balance point of the knife.
The last link in post #2 of the stickies: https://bladeforums.com/threads/sticky-threads-all-the-good-info-you-want-in-one-place.1052730/
discusses this: https://www.bladeforums.com/threads...-stick-and-stay-stuck-on-blade-tangs.1672342/

what epoxy should I use for this?

If it's never going to see use, why worry about it? I know of at least one ABS Master Smith who uses 5-minute epoxy on a regular basis and claims he's not had a single failure in 20-30 years of knifemaking.

 

[Londinium Armoury]

While a lot of makers use this line of thinking as a reason for drilling holes, it is not correct. The reason to drill holes is to reduce the weight of the blade and/or change the balance point of the knife.
The last link in post #2 of the stickies: https://bladeforums.com/threads/sticky-threads-all-the-good-info-you-want-in-one-place.1052730/
discusses this: https://www.bladeforums.com/threads...-stick-and-stay-stuck-on-blade-tangs.1672342/

If it's never going to see use, why worry about it? I know of at least one ABS Master Smith who uses 5-minute epoxy on a regular basis and claims he's not had a single failure in 20-30 years of knifemaking.

2 Drill holes aren't going to reduce the weight and P.O.B really, and in a push dagger they would just be functional to give the epoxy something to grab onto for more points of contact to keep the handle scales on. If you have a large handle with lots of steel then drilling weight reduction holes to lighten the handle works, but on his little push dagger I don't think those 2 little holes should even be classed as weight reduction, it's going to take a gram or 2 off the weight, which won't be noticed. You would need about 10+ holes for them to be classed as weight reduction IMO.

 

[TotallyAutistic]

While a lot of makers use this line of thinking as a reason for drilling holes, it is not correct. The reason to drill holes is to reduce the weight of the blade and/or change the balance point of the knife.
The last link in post #2 of the stickies: https://bladeforums.com/threads/sticky-threads-all-the-good-info-you-want-in-one-place.1052730/
discusses this: https://www.bladeforums.com/threads...-stick-and-stay-stuck-on-blade-tangs.1672342/

If it's never going to see use, why worry about it? I know of at least one ABS Master Smith who uses 5-minute epoxy on a regular basis and claims he's not had a single failure in 20-30 years of knifemaking.

If I ever make a knife which will see use, what epoxy is recommended? If an ABS master smith uses 5-minute epoxy then sure, but I can imagine there being other epoxies that are better in some way

 

[TotallyAutistic]

Plus, what oil is recommended for heat treating? Can I go with a simple oil that you can get in a supermarket or do I really have to order some expensive special heat treating oil like Park's 50 Quench oil