My Little & Large Knife Project

[Emdiesse]

Just looking for advice and suggestions on my next steps Hardening, tempering, sharpening, attaching the handle, etc

I wish to make my own small knife and large knife inspired by the Puukko and the Leuku. This is going to be my first knife project, which I hope to get right. I am doing it because the knife is easily the most used tool in bushcraft and I wish to experience that homemade satisfaction whenever I am out.

My O1 steel arrived yesterday and this has shot me into action to complete some designs. I hope to make these full tang (not traditional, however this is an inspired project not a re-creative one) and the shapes, I wished to include aesthetically appealing curves to the blades. (I found some blade templates here from a user called hedgehog, which I traced and manipulated into something I was aiming for)

How they fit on the 50mmx500mm steel

I made some cardboard models so I could get a feel of the size and shapes of the knives, I fancied adding a bit more of a belly to the big knife (You can see above), and I made the handle a tad longer.

Small Knife: Handle: 110mm, Blade: 90mm
Big Knife: Handle: 120mm, Blade: 220mm

So, I have completed the easy bit and next I hope to start cutting out my blades. First I hope to hear your feedback on the designs since this is my first time and I have little experience with knives other than the mora (of which still I lack experience )

My biggest fear at the moment however, has got to be the heat treatment stage. I understand with O1 steel you can repeat this process if you were unsuccessful the first time however I hope to get it right first time. The reason I fear this stage is because I do not have a pyrometer, nor do I intend on purchasing one. I hope that I can use this resource here and simply go by steel colour. Would a wood fire reach hot enough temperatures?

So, all in all I am looking for advice and suggestions on where to go from here

Thanks

Once I complete this, however long it takes me I hope to then dabble in some leather craft to make a piggy back sheath.

 

[tomongoose]

Have you seen green petes video? he uses a magnet to check when it is hot enough as it becomes non magnetic

 

[PaulSanderson]

hi mate...

they look like great designs. i have made a few myself now, and to be honest, the HT was the bit that worried me too. However, once youre up and running it isnt as difficult as some would suggest. I used a simple wood fire in the fire pit in my back garden, and used a hair dryer to get plenty of oxygen in there. I laid the blade spine down on the bed of wood coals and then pushed the coals along the side of the balde. Once this was done, i used the hairdryer to blow air directly onto the blade until it was glowing red hot all the way through the depth of the blade. I didnt even use the magnet to check if it was at 820-840 degs, i then quenched in oil. Whacked it straight into the Aga afterwards an voila. I must admit, by pure luck i think I have created a really good blade which is razor sharp and holds and edge fantastic...i tested it yesterday for the first time. Its hardened to approx. 58HR which is plenty enough.

Dont be worried about it, just jump in. Its really satisfying, and not that difficult.

 

[Emdiesse]

Have you seen green petes video? he uses a magnet to check when it is hot enough as it becomes non magnetic

Cheers. I have just read that too. I think that's the perfect way for me to do it without spending a fortune. Apparently it's when it reaches the Austenite stage that it becomes non-magnetic and this is the stage when you want to plunge it in oil vertically.

I guess for tempering I can just go by the colours. Do you quench in oil or in water for the tempering stage?

Any suggested Rc hardness rating for the knives?

Cheers

hi mate...

they look like great designs. i have made a few myself now, and to be honest, the HT was the bit that worried me too. However, once youre up and running it isnt as difficult as some would suggest. I used a simple wood fire in the fire pit in my back garden, and used a hair dryer to get plenty of oxygen in there. I laid the blade spine down on the bed of wood coals and then pushed the coals along the side of the balde. Once this was done, i used the hairdryer to blow air directly onto the blade until it was glowing red hot all the way through the depth of the blade. I didnt even use the magnet to check if it was at 820-840 degs, i then quenched in oil. Whacked it straight into the Aga afterwards an voila. I must admit, by pure luck i think I have created a really good blade which is razor sharp and holds and edge fantastic...i tested it yesterday for the first time. Its hardened to approx. 58HR which is plenty enough.

Dont be worried about it, just jump in. Its really satisfying, and not that difficult.

I wish I could take all the credit for the designs, I knew what I wanted in my head but putting it down on paper was hard. Until I found those useful blade designs which I could chop and change to get what was in my head on paper.

Cheers, great tip for the hairdryer. I suppose traditionally they might have used a bellow, fan or blow poker.

Any ideas if O1 steel comes in an annealed state from Cromwell, or do you have to anneal it yourself to make it easier to work?

 

[PaulSanderson]

i quenched in oil, vertically. i read somewhere that water isnt the best to use due to thermal shock, whereas oil quenches slower and hence is better for the integrity of the blade. either way, until tempered it is still brittle anyway.

There is some chart thingamaob over on British Blades which enables you to work out the hardness rating of your blade, its how i worked mine out.

there are way more knowledgeable folk on here, but this is all from personal experience as im a total noob to blade making. got another blade to HT next weekend too...

good luck and keep us posted...

 

[ged]

i quenched in oil, vertically. i read somewhere that water isnt the best to use due to thermal shock, whereas oil quenches slower and hence is better for the integrity of the blade. ...

The 'O' in 'O1' stands for 'Oil' because it's a steel intended for quenching in oil. Don't use water.

See for example

http://www.integritysteel.com/oil-hardening-tool-steel-aisi-o1.html
http://www.hocktools.com/A2.htm

 

[Ogri the trog]

When it comes to tempering, from my little experience, you only see the colours as they flow towards the blues and purples - so my advice would be to either set it in a domestic oven with reasonable temperature controls or err on the side of caution and increase the tempering heat very slowly!

Good luck with it - it does become somewhat addictive!

Ogri the trog

 

[Emdiesse]

The 'O' in 'O1' stands for 'Oil' because it's a steel intended for quenching in oil. Don't use water.

See for example

http://www.integritysteel.com/oil-hardening-tool-steel-aisi-o1.html
http://www.hocktools.com/A2.htm

Cheers, I realised it was O for oil, however the resource I used on heat treating steel said oil for hardening and water when he was at the tempering stage. I thought it could have been a typo because my understanding is it could warp in water? Otherwise I thought perhaps there was a reason for tempering in water. I guess not

When it comes to tempering, from my little experience, you only see the colours as they flow towards the blues and purples - so my advice would be to either set it in a domestic oven with reasonable temperature controls or err on the side of caution and increase the tempering heat very slowly!

Good luck with it - it does become somewhat addictive!

Ogri the trog
http://www.hocktools.com/A2.htm

Cheers, I'll probably use the oven to be on the safe side

 

[PaulSanderson]

just to answer your question about O1 being annealed, its a yes. I got some O1 flat stock from Crowells and it came annealed. I was amazed at the difference in hardness as it is really soft, and very easy to work with just hand tools. Infact i wouldnt recommned power tools if youre ham fisted like me, as chances are you'll end up riping chunks out of it by accident...

...good luck!

 

[lannyman8]

"the resource I used on heat treating steel said oil for hardening and water when he was at the tempering stage."

water is used to temper, you only really do this when selective tempering though..... you put the steel into the water with the bit you want soft upwards out of the water, then you go to work with the blow torch and temper by colour, the bit in the water stays safe not reaching above 100 deg c.....

the best way is in the home oven, use the middle shelf and temper by colour, i use my oven at about 180-190c, but dont relly on the oven dial, keep looking at the steel colour..... have a look at the links below for more details on heat treating etc etc....

http://www.engnath.com/manframe.htm

http://www.threeplanes.net/toolsteel.html

the second link is the on you need for heat treating, it shows the RC and colours.....

hope this helps.....

any questions just PM me dude....

regards...

chris.

 

[Emdiesse]

Cheers for the tips.

So I started work, tonight, on the steel. I decided I would try drilling holes around the profiles of the blade (Leaving a decent buffer for error) to help me cut it out and I drilled 3 holes out the stuff then widened some of the holes large enough to fit a junior hacksaw blade in so I could try and meander around. Anyway, blunted the junior hacksaw blades like they were made of putty (probably crap blades?) Then I used a hacksaw which went through a lot easier. Anyhow, since it is late I have stopped for the night because I am not looking to upset any neighbours with my drilling!

Should I rub some oil in the metal just to look after it, especially the new holes I have made before I continue.

I feel the junior hacksaw might be my best bet because it's manoeuvrable, maybe I just need to get some decent blades for it. cobolt? Perhaps buy some cobalt drill bits to avoid knackering up my dads drill bits too!

 

[lannyman8]

dont bother with the oil as any surface rust will be burnt and pollished off during and after the heat treating (HT)...

a good hacksaw blade is worth the money, drill bits??? i just use normal ones from screw fix but cheep as chips so im not bothered if it snaps or blunts if i make a boo boo......

you need to use a file to make the final shape of the knife, it will take some time but stick with it dude....

regards...

chris.

 

[Emdiesse]

dont bother with the oil as any surface rust will be burnt and pollished off during and after the heat treating (HT)...

a good hacksaw blade is worth the money, drill bits??? i just use normal ones from screw fix but cheep as chips so im not bothered if it snaps or blunts if i make a boo boo......

you need to use a file to make the final shape of the knife, it will take some time but stick with it dude....

regards...

chris.

Ha Ha, cheers.
I don't know why, however I didn't expect the annealed steel to be this tough. On the plus side, they are going to be some tough knives!

I need to get myself a file as well, so I may as well take a trip to B&Q to get myself a few other bits and bobs.

 

[DaveBromley]

Firstly the designs look sweet! as far as heat treating goes its a doddle really, i was worried the first couple of times i did it too but all you need is a decent magnet tbh get your steel up to cherry red colour maybe slightly past then hold it aginst the magnet if it doesnt stick then you have achieved critical temp, I then put it back in the fire for a few seconds to ensure it is back up to temp again then quench in Veg oil.

I go blade first at a 45 degree angle and hold it in for 5 second then out for 2 then back in and leave it in there for 30 seconds, then to check it was successful i run a file over it, if it skips off and sounds like glass you've done it.

then on to tempering, i clean the blade with wire wool first so that i can see the steel clearly then it goes into an oven set to 220 for an hour when you pull it out you should see that the steel has a yellowish (straw) tint to it this means it has tempered to approx 57-59 on the RC scale which is what i go for then leave to cool. Once cool you can sand it and polish it ready to be handled

It sounds like a lot but most if this will happen in about 15 seconds lol and the more you do it ithe easier it will become, worst case scenario you have to start over but that just means more experience

Have fun with it

Dave

 

[ged]

With the possible exception of some power tools, a lot of the tools at B&Q are expensive for what you get, and some are complete junk. It's worth spending some time mooching around as many tool suppliers as you can to get a feel for their ranges of stocks and their prices. If you can find local trade suppliers, some of them will have helpful staff who can give good advice. The 'Engineers' Tools' section of Yellow Pages is a good place to start looking for local suppliers. There is a good market for tools, including second-hand tools, in Chesterfield market square on (I think) Thursdays, I don't know if there are similar markets in other places around the UK but it will be worth a look if you can find one. Some of the new stuff in the market is Chinese junk. Sometimes I'll deliberately buy a junk tool because I know I'm going to abuse it to destruction.

If you use a file to check your blade is hardened after heat treatment, use an old or cheap one! You can chip the teeth on a file that way and much reduce its efficiency. Don't let your files, drills and other metal cutting tools (nor your dad's!) go rusty.

Hacksaw blades like the 'junior' type are not usually high speed steel (HSS), they're a kind of tool steel -- which is what you're making a knife with, so it shouldn't be too surprising that they don't last very well. You can get blades like this to fit the 'junior' hacksaw and similar which can make cutting odd shapes easier. Also consider a coping saw. High speed steel saws which are 'all hard' are also all brittle, so they shatter easily. After you've broken a few you'll know just how easily and will break them less often. Bi-metal blades will take a lot more abuse because the teeth are HSS but the back is softer and so will flex more without breaking. If you can get a heat treat like that on your knife it will work exceptionally well but the bi-metal blades are actually two different steels welded together You can't hope to do anything like that in your shed at home. Bi-metal blades may be slightly more expensive but the first one you don't break will pay for itself. Both HSS and bi-metal blades will usually be painted, unlike the blackened 'junior' and other cheap hacksaw blades. The 'speed' in high speed steel refers to the cutting speed.

When you're using a drill, try to make sure that it's always cutting. If it slips and skips on the workpiece it will generate a lot of heat. In a fraction of a second this can heat treat the surface of the workpiece that you are trying to cut through, and the drill too. This may simultaneously give you a harder workpiece and a softer cutting edge on the tool. Result, misery. You need a steady but not excessive pressure on the drill to make sure the cutting is continuous. While drilling there should be a continuous spiral of metal coming from each of the two drill flutes. Ease off the pressure as the drill breaks through the back of the work or the drill may suddenly bite too deep and chip or break. These things are a little difficult to explain, you will need to get a 'feel' for it. That may cost you a few drills and hacksaw blades.

 

[Emdiesse]

Firstly the designs look sweet! as far as heat treating goes its a doddle really, i was worried the first couple of times i did it too but all you need is a decent magnet tbh get your steel up to cherry red colour maybe slightly past then hold it aginst the magnet if it doesnt stick then you have achieved critical temp, I then put it back in the fire for a few seconds to ensure it is back up to temp again then quench in Veg oil.

I go blade first at a 45 degree angle and hold it in for 5 second then out for 2 then back in and leave it in there for 30 seconds, then to check it was successful i run a file over it, if it skips off and sounds like glass you've done it.

then on to tempering, i clean the blade with wire wool first so that i can see the steel clearly then it goes into an oven set to 220 for an hour when you pull it out you should see that the steel has a yellowish (straw) tint to it this means it has tempered to approx 57-59 on the RC scale which is what i go for then leave to cool. Once cool you can sand it and polish it ready to be handled

It sounds like a lot but most if this will happen in about 15 seconds lol and the more you do it ithe easier it will become, worst case scenario you have to start over but that just means more experience

Have fun with it

Dave

With the possible exception of some power tools, a lot of the tools at B&Q are expensive for what you get, and some are complete junk. It's worth spending some time mooching around as many tool suppliers as you can to get a feel for their ranges of stocks and their prices. If you can find local trade suppliers, some of them will have helpful staff who can give good advice. The 'Engineers' Tools' section of Yellow Pages is a good place to start looking for local suppliers. There is a good market for tools, including second-hand tools, in Chesterfield market square on (I think) Thursdays, I don't know if there are similar markets in other places around the UK but it will be worth a look if you can find one. Some of the new stuff in the market is Chinese junk. Sometimes I'll deliberately buy a junk tool because I know I'm going to abuse it to destruction.

If you use a file to check your blade is hardened after heat treatment, use an old or cheap one! You can chip the teeth on a file that way and much reduce its efficiency. Don't let your files, drills and other metal cutting tools (nor your dad's!) go rusty.

Hacksaw blades like the 'junior' type are not usually high speed steel (HSS), they're a kind of tool steel -- which is what you're making a knife with, so it shouldn't be too surprising that they don't last very well. You can get blades like this to fit the 'junior' hacksaw and similar which can make cutting odd shapes easier. Also consider a coping saw. High speed steel saws which are 'all hard' are also all brittle, so they shatter easily. After you've broken a few you'll know just how easily and will break them less often. Bi-metal blades will take a lot more abuse because the teeth are HSS but the back is softer and so will flex more without breaking. If you can get a heat treat like that on your knife it will work exceptionally well but the bi-metal blades are actually two different steels welded together You can't hope to do anything like that in your shed at home. Bi-metal blades may be slightly more expensive but the first one you don't break will pay for itself. Both HSS and bi-metal blades will usually be painted, unlike the blackened 'junior' and other cheap hacksaw blades. The 'speed' in high speed steel refers to the cutting speed.

When you're using a drill, try to make sure that it's always cutting. If it slips and skips on the workpiece it will generate a lot of heat. In a fraction of a second this can heat treat the surface of the workpiece that you are trying to cut through, and the drill too. This may simultaneously give you a harder workpiece and a softer cutting edge on the tool. Result, misery. You need a steady but not excessive pressure on the drill to make sure the cutting is continuous. While drilling there should be a continuous spiral of metal coming from each of the two drill flutes. Ease off the pressure as the drill breaks through the back of the work or the drill may suddenly bite too deep and chip or break. These things are a little difficult to explain, you will need to get a 'feel' for it. That may cost you a few drills and hacksaw blades.

Brilliant advice guys on the hardening, tempering and working of steel. I'll have to work on the drilling, I think before I was probably doing just what you said about the bits sliding and creating heat on the steel.

These are probably going to be the hardest knives I ever make, I guess it gets a lot easier with experience. It will also be a lot easier hearing advice from people who are more experienced.

I'll be going careful with the drilling and sawing from now on, last thing I want is to make it hard for myself by heating and hardening the steel from working!

Thanks