Introduction: Drop Point Pocket Knife
This knife is by far my most favorite to have made so far, it was a fun project to design and make. It is heat treated to get a keener edge on it but other than that, it was not rocket science.
Certainly a great knife to have on you for those times you need to slice, cut, chop, pare, trim, or hack!
This is made out of an old circular saw blade so here's your chance to recycle one you would have otherwise thrown out.
Circular saw blade
Angle grinder (or hacksaw)
Sandpaper (grits 200-2000)
Wood for the handle
Some kind of Fire/kiln to heat treat it
Oil stone or whetstone
Step 1: Drawing the Design
To start with you are going to need to draw the design of your knife. You can copy mine or create your own design if you want. I wanted a knife that could easily fit in my pocket but not so small that I could not do any thing with it. This design fits my hand nicely and is pocket size. What I found helpful was to draw up the design then put it onto cardboard, cut it out and then see what it felt like in my hand. I experimented with different shapes and sizes until I came across one I liked. Once I found the design I wanted I copied it out onto the saw blade. For the saw blade I found an old, used one which was blunt and would have otherwise ended up in the trash pile.
Step 2: Cutting It Out
To cut it out I used an angle grinder. You could also use a hacksaw, it just takes a bit longer but it would still do the job. I cut out the knife outside, so as not to burn anything down - as a lot of sparks are created! You will need ear muffs and safety glasses for this step. Clamp your work piece to something sturdy before you start cutting. Cut along both edges of the knife then rearrange the blade under the clamp and neaten up the handle. To make it easier to cut out the handle, make a series of small cuts every few mm along the handle and cut along the notches, this makes it easier to cut closer to the drawn line.
Step 3: Tidy It Up
Smooth off the rough edges using a bench grinder or file.
Take off any rust by laying the knife flat on a sanding belt until clean. (You can use sand paper and elbow grease too but this takes a lot longer)
When doing this make sure to dip it in water every few seconds so as not to burn your fingers and keep the metal properties right. If the metal properties change you may not be able to heat treat it anymore. When sanding with the belt sander make sure you use a fine grit paper (240 or more) as a coarse grit will leave scratches which will be nearly impossible to remove later.
Step 4: Creating the Bevel
When creating a bevel it is important to get it in the middle of the blade otherwise you will not get a sharp edge and it will not cut straight.
Use either a bench grinder, file or belt sander to create the bevel. A belt sander does a great job and leaves a relatively smooth finish, whereas a bench grinder on the other hand leaves quite a rough finish. Creating a bevel with a file is also possible, it will take a bit longer but is a lot more precise.
With the belt sander I have I can't create a bevel on a thick piece of steel as the sanding board underneath the sanding belt gets in the way. To do thicker pieces of steel you need a strap belt sander which has a vertical belt instead of a horizontal belt and the sanding belt is only about 4-8cm wide.
When creating the bevel on a belt sander or bench grinder remember to keep dipping it in water to keep it cool.
Hold the knife at about 20 degrees while sanding to get a slight bevel so it can get razor sharp. If you want it to have a bit more strength to the blade do a 30 degree angle or if you want it to be razor sharp do a 15 degree angle.
Step 5: Sanding
Once you have created the bevel you will see that it is quite 'rough'. To save time later make sure you sand it before heat treating it. This will save time later because non heat treated metal is easier to sand than heat treated metal.
Sand at about 200 grit to get a reasonable smooth finish. You can go finer if you want. Sanding it after heat treating, at a higher grit, will make your sand paper clog up quickly because of oil residue left on the blade after quenching.
Step 6: Heat Treating
Now for the more complicated part, heat treating the blade.
For heat treating you will need some kind of fire or forge. I use a small wood burner, which does a great job for heat treating the knives I make. If you don't have a forge or wood burner you could just make an open fire in a pit outside. This works as well but to get it hot enough you will need to use something like a hairdryer, with a tube attached to the end (so you don't melt your hairdryer!), to give the fire oxygen, so it gets hotter.
The kind of metal you have used will decide how you should heat treat it. If you have never done this before I highly recommend following this instructable first.https://www.instructables.com/id/Heat-Treating-Knives/
You can test sample pieces of the same piece of metal you used for the knife and heat it up in your fire until it gets bright orange and non magnetic. Once it is bright and non magnetic quench the piece of metal in some vegetable oil (old vege oil is fine to use) You can also use water but it is more likely to snap the blade. Take the metal straight from the fire and quench it in the oil as not to let it cool down too much.
Once the piece has cooled down put it in a vice then get a plumber's wrench and bend the piece of metal to a 45 degree angle. If it snaps while you are bending it then you good to go. But if it does not snap and just bends then try heat treating at different temperatures till you get it to snap.
Once you have tested if the metal is able to be heat treated then get your blade and heat treat it.
These are the steps to heat treat
1. Get the fire really hot
2. Get some oil ready
3. Hold your knife with a wrench and place it in the fire..
4. Leave it in the fire and wait until the blade is bright orange and is non magnetic (take out briefly and test with a magnet)
5. When the blade is bright orange quench it in oil
6. Keep it in the oil for a few seconds
Step 7: Tempering
Once you have heat treated the knife you will need to temper it. What this does is, it softens the metal slightly so it is not so brittle, because after heat treating it, it will be very brittle.
You can temper the blade at different temperatures.
The lower the temperature you temper at the harder the blade will be but not as tough.
The higher the temperature you temper at the tougher the blade will be but it will not be as hard.
For a kitchen knife you probably want a harder blade so temper at 200-250C
For a Hunting knife temper at 250-350C as this will get a very tough blade (I tempered mine at 275C)
Make sure when tempering the knife do it twice. Use 2x2 hour cycles - letting the knife cool to room temperature in between before putting it back in for another 2 hours.
Step 8: Sanding to Make It Shiny!
After heat treating the blade you will find that there is black stuff on the blade. This is oil residue from the heat treating that has burnt onto the knife.
Clamp your knife to your work bench or put it in a vice to hold it. Get 200 grit sandpaper and sand off the black residue, once all the residue has been removed take 400 grit sandpaper and sand the blade. What I found helpful while sanding was to wrap the sand paper around a square piece of wood about 2x2cm (sanding block) this gives a flat sanding pad surface and it gives a better finish. Once you have used 400 grit, sand with 600 grit then 1000 then 2000. You can even do 3000 grit if you want to but I find that 2000 grit does a great job.
Now to protect the blade while you are making the handle you can wrap it in masking tape. (I accidentally used tape similar to masking tape but it was a lot more sticky and I spent an hour getting it off -do as I say not as I do;)
Step 9: Making the Handle
Now the knife needs a handle.
For the handle I used a piece of black walnut which I had lying about. For a handle it's best to use a hard wood of some kind as this will last longer and probably look better too. I find the best thickness of wood to use for a handle is about half a cm thick, this means you can sandwich the knife between and the thickness will total just over 1 cm.
Get your knife and copy its handle pattern onto the piece of wood you are going to use. Cut it out with a scroll saw or coping saw. Make sure the sides that are going to be glued to the knife are level to get a nice glue up. For gluing I used 'liquid nails' which works really well. You can go for the more expensive option and use an epoxy of some kind which will probably last a bit longer.
Make sure you clamp the handle while the glue is drying to make sure you don't get any gaps in the handle for water to seep in later and destroy all your hard work.
Step 10: Finishing the Handle
When the glue is dry you can take the clamps off. There will probably be excess glue, which squeezed out, you can remove this with a chisel. Once you have removed the excess glue use a file to get to the metal of the handle. Get some 100 grit sandpaper and round the corners and edges to get a nice comfortable fit for your hand. When you are happy with the shape use 200 grit then 400 grit to get a nice smooth finish.
Now all it needs is the oil to protect it and make it look nice. I use linseed oil on my knives. With oil it pays to do a few coats about 20 minutes apart to let the oil soak in.
Remember with linseed oil to make sure you dispose of the towel you used to apply the oil (as linseed oil can self-combust as it dries out)
Step 11: Sharpening
Now to give it a sharpen
I use an oil stone when sharpening my knives. This gives a great edge to the knife and it is not that hard to resharpen the blade later.
Get an oil stone or whetstone (mine is 300grit on one side and 500grit on the other side)
For an oil stone just pour a little bit of light oil on the wet stone and rest the bevel of your knife on it. Hold the knife at about 20 degrees to the stone and slide it back and forth. To make sure you are getting the whole bevel sharp you can use a marker and put ink along the bevel, let it dry and sharpen it again this time checking to see if all the ink is gone (this means you have sharpened the whole surface if all the ink is gone).
For a whetstone just soak it in water until it can not absorb any more water then do the same as above.
Now strop the knife with leather to get it even sharper. What stropping does is helps raise, a slightly rolled-over edge, (or burr) back up. This will restore an otherwise intact edge to full sharpness. You don't need to press too hard when stropping just let the weight of the knife do the work. Strop at the same angle as you sharpened it with the stone.
Step 12: Sheath
If you want to, you can make a sheath for your knife to protect it.
I used a piece of scrap leather I had lying around and drew around the edges of the knife then did a mirror image a few cm away. This gives you room to trim and glue the sheath. Use super glue or fabric glue to hold the leather together and peg it while the glue dries. Once the glue is dry trim the edges to make it neater. Then put the knife into the sheath!
Step 13: Admire Your Work!
Now you have completely finished the knife! I hope you enjoyed this instructable!
Here are a few tips when making knives....
1. Patience. You need a lot of patience to make knives!
2. When sanding your blade make sure you spend a lot of time doing this because one small scratch can ruin the looks of your knife.
3. Make sure you keep the knife well oiled because it will rust overnight if you don't. Just use a paper towel with oil on it and just wipe down the knife blade with it.
Thanks and happy creating,
Participated in the
Pocket-Sized Speed Challenge