Toolmaking – Forge Your Knife

Toolmaking – Forge Your Knife


This video resource will cover the techniques for making a knife. We will be covering the following things: And then I will take you through each of the steps for: Before you start any kind of work in the workshop you want to make sure you are well protected. In this case we have got: If you get burnt put it under water for 20 minutes to get all the heat out of the affected part. But if you take care it shouldn’t happen. The other really important thing to think about is a really intese fire is going to produce a lot of UV light So you will want to keep your hands and arms and face protected. This is an angle grinder. I’ve got 3 different kinds of cutting blades here. This first one is a very fine one which is ideal for making the initial cut in the piece of spring steel. The second one here is a grinding disk and its purpose is to remove the metal to make a form or shape. And the third one is a flat disk. This one is really good for doing some initial polishing. Later on I will show you how to use the linisher, a big flat sanding belt, to give you nice flat surface to your tools. This is a heavy 1.8kg hammer. It is essential for moving metal and flattening it out. This is a planishing hammer which is great for flattening out all the dings and bumps that 1st one will make. You will need both of these. It is important that you match up the tong to the piece of steel you’ve got, so you have a good comfortable grip. This is a car spring, it usually comes from the front of a car. The last thing we are going to need to make our knife is a furnace. What we’ve got here is a gas fired forge, it is a small box forge. That will get us our temperatures we need to make our steel that lovely golden colour that means it is soft enough for us to shape. The next step is to draw out the design you’ve got in mind. When you draw the knife you want to make sure the drawing is life-sized because you are going to cut that out and use it as a template when you get to the shaping stage. Keep in mind if you’re making a knife for kitchen use, you want to give enough room for your knuckles to fit underneath the handle. Now we are going to get on with the action. The first thing we have got to do is cut off a piece of the spring. And now we need to make it into a flat bar. The technique is to hold it by the end lay it across the face of the anvil. Make sure it is bright red or orange colour but don’t let it get any hotter than that. If you see little sparks occuring on the side of it then the carbon is coming out of it and we don’t want that. At this stage you are using the heat of the forge to soften the material so you can shape it It is really important to get that overall shape working. If we look at this knife here as it comes from the handle down to the point you need to push the metal out and flattening it out and making it finer towards the tip. And likewise, from the back of the blade through to the sharp edge of the blade making sure there is an elongated V-shape happening there too. In terms of this part here, the shape and pattern of the handle, that is something you can tune-up later on with an angle grinder. In this blade we have done our initial forming and now it is time for a bit of shaping. The shaping is going to give the finished outline to it and what we’ll need here is the template that we drew and cut out earlier. Draw a profile onto the blade then grind it out on the grinder, and that will give you pretty much the final shape. At this stage you can also start to do the linishing to flatten out the blade and taking out all of the hammer marks. The next step is to replace the carbon that we’ve taken out of it during the heating process. Heat the knife up to a red heat and then put it into a container of sawdust That will make sure that the carbon lost druing the heating process is brought back into the skin of the steel making it a good hard blade ready for sharpening. At this stage the blade is very soft. We have put the carbon back into it and it is now ready for hardening. What we have to do is preheat some linseed oil to about 40 degrees celsius then get the blade up to a nice bright red. You test it is ready by putting a magnet against the blade. If the magnet doesn’t stick to the blade then you know it is at the correct temperature. Then quickly put the blade into the oil and stir it around for about 20 seconds. Moving it around makes sure you get fresh oil up against the entire skin of the hot steel, and gives an even cooling. When you have finished the hardening process, take the blade out of the oil and clean it off with methylated spirits. Now it is ready for the tempering. Preheat an oven up to 210 degrees celsius, put your blade into that and leave it there for half an hour. Turn the oven off, let it cool down, then take the blade out. That is the first stage of the tempering done. For your spring temper place the edge of the blade between two sheets of metal, clamp it in a vice and then hold the flame at the point above where the blade and the metal meet until the knife turns blue and then push that blue colour along the top, don’t let the blue colour come down to where the actual edge is though. just run it along… it is just like painting with the flame torch really. This is a piece of Jarrah which is a wonderful Australian hardwood which makes fantastic handles. This is a piece of Manuka, it could just as easily be used to make a handle. Any decorative wood can be used, probably tending towards the hardwood variety is better though. To put the handle onto the knife go back to the original pattern and look at the shape you want to use. Draw it up and cut it to shape. Get a feel for what it will be like when it is fully assembled. How wide is it? Does the curvature work in your hand? Particularly along the edges, you want to make sure they are nicely smoothed off. I’ve got a bit of brass rod here. These holes here were drilled to match the thickness of this particular rod. Cut your length of brass and then using a two-part glue which will set hard. Coat both pieces of the wooden handle, put your pins in, squeeze it in a clamp and let it set. Once it has set grind and sand off the glue and shape and you are finished. Just remember that this might be your first blade but I am sure once you get into it you’ll probably want to make more. The more you make the more you tune up the process.

88 thoughts on “Toolmaking – Forge Your Knife

  1. @cejason Hardwoods such as ebony will work well for handles. Soft woods such as pine or willow may not be as durable. Depending on where you live it is worth exploring a range of timbers for their picturesque grain patterns and colours. Laminating different woods can work very effectively as well – use an epoxy glue and let it set before an initial clean up then finish by sanding with a high grit paper when glue has fully hardened.

  2. @Looneydude2398 A cold grind should not affect the carbon content. Carbon loss of any significance mainly occurs with excessive heat – at a light yellow to white heat sparks can be seen forming on the surface – carbon loss is occurring. Carbon can be replaced by heating your blade to orange heat then placing it into a can of sawdust and putting a lid on to exclude oxygen – reduces fire risk. Leave it here to cool. Then follow up with usual heat treating and tempering.

  3. @KillaNoco123 I use boiled linseed oil though I have heard of people using old engine oil as well. Not sure about corn or olive oil??? You might need to ask on one of the many knife makers bulletin boards on the net.

  4. @LearningConnexion i see thank you. reason i asked is because i wouldn't want to use an oil i shouldn't be putting into my mouth

  5. great video thanks for posting, if anyone knows of a blacksmiths/bladesmith course around newcastle please let me know, thank u

  6. this is a little late, but once it has been quenched you can wash the oil off, and it will never get into your mouth. but olive oil or vegetable oil works too, the reason people use old engine oil is to add to the carbon content in the steel.

  7. Nice video, however I believe your thoughts on carbon replacement are flawed. There is not enough time at temperature with the method you show…

  8. Amazingly well scripted and informative video! I am in the middle of making my own knife and this has helped me with the next steps. Thanks so much!

  9. I'm in abut my 6th yr as an amateur knife smith and to see more of these video's popping up here on YouTube is just fantastic.

  10. The hot blade is placed into a container of dry sawdust and a lid is placed on top to seal off the air – this avoids fire.

  11. I bought three feet of Hardened steel. I cut some out to make a machete.
    Its still rectangular and three inches wide and maybe a foot long. idk how thick but its a good thickness.
    I want to keep the rectangular shape and just put sum para chord as the handle and sharpen an edge of it. yes i know, lazy and not crafty but i want to start of easy since I will be doing everthing by hand.
    anyways, after sharpening- Do I temper it?? and I dont have to re harden it do i? HELP ME ASAP!!! please(:

  12. Looks like you will have your work cut out for you on this one which ever way you go. If you have heated the steel in the cut-out process you will have partially annealed (softened) it reducing its effectiveness as a cutting instrument. The other part should still be hardened making it difficult to form or drill by hand. Suggest you go back to the steps covered in the DVD. Anneal (soften) the steel, form it, harden, temper, polish, attach a handle, sharpen, use with care!

  13. Can you use a rubber mallet and a regular hammer to forge cause i know how to forge but can i use these?

  14. A rubber mallet will not work – the heat will cause the rubber to melt. A regular hammer could work as it is hardened steel – however, better to use either a ball pein hammer or small sledge hammer – depends on your strength.

  15. This DVD was filmed over a two day period here at our Learning Connexion campus. Usually, a three day class will ensure all seven students complete at least one blade – possibly another. Working by myself I could finish a blade in a day – I expect knife makers with more experience and a hydraulic press could make a run of them and work up two or three in a day.

  16. Thanks, we script and plan our videos to the last detail as we use them as resources for our distance students. Thanks for your comment.

  17. We are based in New Zealand and our website is tlc.ac.nz
    We also offer correspondence classes for students not able to come onsite to us in Wellington NZ.

  18. Suggest you contact the manufacturer for specific details. Generally though, if it is suitable for springs on a car it is fine for making a knife from. Have a look at the details on Wikipedia for high carbon spring steel.

  19. This is Not. Forging a knife. This is stock removal claiming to be "Forged" because he hit a truck spring with a hammer. And you're not heating up the steel hot enough.. You're barely hitting Aus. temp, you need to be forging at 1650-1850 F. Don't be fooled friends.

  20. Thanks Liam. I see your point, the title is perhaps misleading. More accurate to have titled the video 'Knife Making by forging and grinding'. As the video shows, a coil spring is forged into a formed blank then this material is removed by grinding / sanding. Stock bar is not the source material.
    Re temperatures. We use the Celcius scale – see the oven shot and heated steel colour – temperatures about 900C+ – (1652F) – more than hot enough to forge work the coil spring.

  21. Pleased that it has helped you. Do check out the many other knife making videos on you tube. they all have useful bits of information and different approaches.

  22. The steel does need to be above curie temp. to forge it correctly. If you have any understanding of what happens to steel after you heat it and cool it and hit it while it's cold then you will NOT forge under 1450. Much less forge a knife blade that cool. It can ruin your steel. Forging steel that cold can cause a lot of micro fractures in high carbon steel.. and very easily if it's 52100, a2 etc. etc…. Learning how to forge is a giant step in making quality knives and tools.

  23. are you fucking stupid of coarse it needs to be hot, else the steel is likely to break, steel isnt like aluminium or other metals, that can be cold forged.

  24. Nice video. Good heat treatment tips. I have found it to be most tricky. Love the sawdust tip. I have made several knives, but have used coil springs only for punches and chisels. Will have to try this.

  25. Nice vid. i just started bladesmithing myself, i use the stock removal method and someday would like to learn to forge knives. i subbed.. thank you.

  26. You can do this in the Certificate Programme, as it is also run as a weekend class, which is open to fee paying students and casual students.

  27. They would actually forge the blade to shape and finish with files and stones.. This individual hasn't refined his hammer work or heat control yet so he has to use far more grinding than a bladesmith ever would have to resort to.

  28. Not with the method he shows. What he is doing would result in a very poor case hardening if he had used a material with more carbon and held it at a temperature where the carbon could go into solution in the steel. The temperature he was working with was too low to allow carbon migration into the crystal structure with anything less that a product such as Casenite. Start with a quality steel with the carbon content your project requires.

  29. Can I use old motor oil for the hardening process. I go through on average 100 galons of motor oil a month just to keep my fleet of tractors running. Would that make a difference if I used the old oil from that to do hardening?

  30. It is fast and effective method to make a blade for beginners. No reason to complain – hammering blade to exact shape is not so easy . Temperatures were all correct (why commentators are thinking temp. is low?). Spring contains carbon enough. What is quality steel? Dif. steels for woodwork, skinning, digging. Oil or water quenching depends of the steel. Using old motor oil is common. You can quench only the cutting half of the blade. The blade must not be sharp at all – then its warping easily.

  31. NEVER use an oven. the metal will release fumes that can kill you. the oven traps those fumes and bingo, youre poisoned.

  32. you can use an oven, the steel wont release fumes unless its galvanised. if it is galvanised it probably isnt suitable for knife making anyway. Where do people get this information?

  33. Why would you not try to forge it more to its final shape and if there is excess… hot cut it off….. then to just flatten a bit of steel and go at it with grinders?

  34. Hello from USA! Warning!! knife making is addicting; It keeps you keep aquiring tools. I really enjoyed your video. How does the sawdust add carbon to the spring steel? Thanks mate

  35. You need to forge your knives closest to the finished product as possible instead of doing all of the grinding, but i guess thats just an opinion

  36. Where is the best place to find a car spring? Is there a place I can order online, or would some kind of junkyard be willing to give one up for free or for a small cost?

  37. yes i mean it. even i was very sad since i workout well for abs but nothing was coming. btw!but ye My international body building trainer also recommended this 7 food elements to kill your fat belly. i found it here -> bit.ly/11dPCXh?=mstgy

  38. Man! You remind me of my dad, I hail from India, and from a traditional Blacksmith family, My father used to teach me all these stuffs when i was small. 🙂 Would surely use your ways of making knives.

  39. Rather than drawing on the metal, you can glue the paper onto the metal, grind, and then lightly heat it to melt the glue.

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