DIY Knifemaking: 2 tactical blades

[brihacharan]

Knife-Making
www.hansoncustomknives.com/Knifemaking101.html

Here’s an excerpt from the above article:

Foreword:
Knife-making like blacksmithing is 80% mind and 20% muscle. If you think you can make a knife you can, if you think you can’t make a knife YOU CAN’T.

I continually hear people lament that “I can’t forge weld”, “I can’t make a knife”, “I can’t do this or I can’t do that”. Every time I hear someone say I can’t, I reflect on the words of Bill Epps: “I remember old I Can’t, the dumb SOB died in the poor house.” You must have confidence in yourself and your abilities before you can do anything well so park the negative attitude at the door. You can and you will make a knife. It is really not that hard. If you can forge steel, you can make a knife.

You will need to avail of a little knowledge about various types of steel that make good blades and how to properly handle that steel to produce a quality blade.

There are no magical or mysterious processes that produce an exceptional blade. Each type of steel reacts to a certain set of conditions in a certain way and it reacts that way every time. You must learn how to handle and treat the type of steel you select to use.

STEEL TYPES:
In order to make a blade, you must know what steel you are working with. I would recommend that you start with 5160 which is spring steel or some of the plain Carbon Steels in the 1075 to 1095 range. I generally use coil or leaf springs. Truck Coil Springs are either 5160 or 1095 and Truck Leaf Springs are 1085. Auto Coil Springs are 4360 or 1095 and Auto Leaf Springs are either 5160 or 1085. There are many that swear by old files for knives.

PREPARING THE STEEL:
Let’s say that you have acquired a piece of leaf spring from a car, first clean it up with a wire brush to get most of the gunk and rust off of it. Inspect it for obvious cracks or fatigued areas. Then cut it into manageable chunks with a chop saw or hot cut. After the material is in manageable pieces, you should anneal the steel to make it as workable as possible. Heat the piece or pieces of steel to a bright red and drop them into a bucket of ashes, lime or vermiculite. Let them cool overnight. Now you are almost ready to start your blade.

FORGING THE BLADE:
Decide if you are going to make a full tang knife or a hidden tang knife. A full tang knife is one where the handle scales are just riveted to the tang and the tang and the handle are the same shape. The edges of the tang are visible. The hidden tang is one where the tang goes through the center of the handle and the tang is not visible.

Check this website http://www.principalmetals.com/ > property data > for proper temperatures for working the metal. This site also had great information on heat treating and tempering various steel types.

HEAT TREATING AND TEMPERING:
Note that heat treating hardens the blade, tempering softens the blade and removes brittleness to the desired level. They are not one and the same. Once the blade is rough ground, heat the blade to just above the temperature that it goes non-magnetic. On some steels it is desirable to hold at this temperature for a few minutes.

Check http://www.principalmetals.com/ for proper time and temperatures. I like to hold the piece at temperature for about 5 minutes. I generally heat the piece to bright red, remove it from the forge and stamp my touch-mark into it, then return it to the forge and bring it back up to heat. Once the piece has reached the proper temperature, quench it in oil to cool.

FINISH GRINDING AND POLISHING:
Once the blade has been tempered, check it for any warping that may have occurred in the heat treating and tempering process. You can do this by laying it on a perfectly flat surface, first one side then the other. Look to see if there is any daylight under the blade. If the blade is slightly warped, you can take the warp out with the belt sander.

Start by clamping a piece of angle iron in the vise, and then use a C-clamp on the tang to secure the blade to the angle iron. This gives me a rigid flat surface to work on. I take a piece of 1” X ¼” flat bar and wrap the sand paper around it. I start with 150 grit sand paper and remove all marks made by the 120 grit belt. Then I progress with 220, 320, 400 and 600 grit to make sure that all marks from the previous grits are removed completely.

Once I have finished with the 600 grit, the blade has a fairly polished appearance. I then move to the felt wheel on the buffer. I buff the blade with black compound first, then switch to white and buff again. This gives a very high polish to the blade. I then finish by hand sanding with 2000 grit wet or dry sandpaper followed by red rouge on a cloth and finally polished with paper towel.

PUTTING ON THE HANDLE:
First decide what you want to use for handle material. The selection of materials range from local Hardwoods, to exotic Hardwoods, to bone, various horns, man- made materials like Micarta, Plastic and resin products.
Full Tang Handle: If your choice is a full tang handle, you must first cut and fit the hand guard or bolsters and rivet in place. Many people like to put some solder or silver solder under bolsters or solder the guard in place before riveting. This forms a tight seal to the blade and keeps moisture out from under the hardware. A butt cap or bolsters, if you are planning to use one should also be secured to the end of the tang. The scales, slabs of handle material, are then just fitted and glued in place. Some people drill the tang for rivets before putting on the scales, I prefer to glue everything in place and then drill the whole works at one time. If you do it this way, put a piece of wood under the knife handle to prevent the drill bit from tearing out a chunk when it comes through. Your choice of rivets range from store bought to home made. Some people use 1/8 inch brass welding rod for pins and peen over the ends. There is also a wide variety of store bought mosaic pins that are available or you can once again make your own. Use a rasp, belt sander, file and sandpaper to shape the handle to your taste.

HIDDEN TANG HANDLE:
First you must cut and fit the hand guard if you have not purchased a pre-made one. I use 3/8” thick brass stock to make my own. I cut the piece for the hand guard, mark the size of the tang on it then drill it with the appropriate sized drill bit.
I use a cold chisel to cut out the material between the holes then do the final fitting with a file. Once this is fitted, I put heat stop paste on the blade just below the guard and silver solder the guard in place. I don’t know what it is called, but I find the silver solder with the blue flux works the best for me. It melts at a low temperature and is very strong. I then cut off the end of the tang to a suitable length and braise on a quarter inch coarse thread bold that has the head cut off.

You can use a smaller size machine screw if you desire. I take the piece of brass stock I will use for the butt cap and drill a half inch hole approximately half way through it. I set a ¼ inch nut in the hole and silver solder it in place. Putting a bolt in the nut and taking it out as soon as the solder is set will keep the threads free of solder. Have a couple pairs of pliers handy for this. Now grind off the nut flush with the brass. Now all you have to do is put a groove in each handle scale, then place them over the tang apply 10 minute epoxy to the edges and clamp them together. Now pull them off the tang still clamped together before the glue sets.

Decide what spacer and accent material you want to use and cut them the same size as the handle and then cut the hole in the center for the tang. Some common spacer materials are pieces of various colored plastic, thin pieces of brass, copper, or aluminum, thin pieces of wood of a contrasting color, or leather washers. You are only limited by your imagination. Once the glue on the scales has dried, dry assemble the handle and screw on the butt cap Adjust the butt cap for the tightest possible fit by adding spacers or by using the belt sander to grind off a small portion of the bolt on the end of the tang. Once everything fits tightly, disassemble the handle, mix a good amount of 5 minute epoxy then apply glue to each side of each piece as you assemble it.

Get as much glue inside the handle as you can. Once everything is in place, apply glue to the butt cap and screw it securely into place. Once the glue is dry, use a belt sander, rasp, file, sandpaper or more likely a combination of several of the preceding to shape the handle to you taste and fit. I shape the butt cap and hand guard at the same time I shape the handle using the belt sander.

SHARPENING:
The last thing I do is sharpen the knife. Why, because I like my fingers all 10 of them!!! I put tape on the blade to protect all but the area I will be sharpening. I use a 120 grit belt on the belt sander to do the rough sharpening. Then I clamp the knife to a board or piece of angle iron in the vise and carefully sand out any scratches made by the belt sander. By working on the slack part of the belt on the sander, scratches are kept to a minimum. Once the scratches have been removed, finish sharpening on a wet or oil stone & then polish the edge of the blade with 2000 grit sandpaper.

Remember that it is not the destination that counts - it is the journey to get there. Enjoy the ride.
Briha

[astronomy.domaine]

Great article Briha sir.! Thanks for posting..

[astronomy.domaine]

@kshitij: I don't dwell too much on strengthening blades by heat treating. Have tried it in the past but didn't get the expected results. Most probably because metal dealers of the local variety are quite clueless about the composition of the steel they sell and, at least for me, its impossible to know the credentials of a metal by just looking at it. Heat treatment being an exact science, defeats the whole purpose if the steel composition is unknown.
I mostly pick steel which is pre-tempered to some extent. i.e. tool grade steel (chisels, files..etc), industrial shearing blades, steel from leaf springs. All these sources would yield a hardness of at least 56/58hrc to as high as 60/62hrc, with which, I am quite content. I use a very 'desi' approach for selecting SS (which I use very rarely). I just take a small file with me and test it on the steel samples shown to me by the dealer...
The one most resilient comes home with me... . that's it.
As far as a mirror finish is concerned, it can be done on any steel or iron, stainless or not.

[kshitij]

Your reply is testament to what we indians can accomplish even with the limited resources available locally to us. Hat tip to you too for this.

No one can guess grade or composition of material just by looking at it, thats why we have material test certificates

I too stick to making my knives from high carbon steel used in saw blades, specifically because they come hardened and tempered in the sheet form itself. Only problem is that maximum thickness of those kind of sheets available is 3.5mm.

Most metals can be polised to a mirror finish just dont see the point in polishing any blade other than the ones made in stainless steel to a mirror finish as no matter what you do it going to rust n pitt sooner or later

Have figured out a jugaad to get the SS blades heat treated. Will post the results if successful, if not then will stick to carbon steels only

[astronomy.domaine]

Your reply is testament to what we indians can accomplish even with the limited resources available locally to us.

well,, why deny yourself the joy of knife making and just wait for all variables to be perfect...

I too stick to making my knives from high carbon steel used in saw blades, specifically because they come hardened and tempered in the sheet form itself. Only problem is that maximum thickness of those kind of sheets available is 3.5mm.
]

try using some good quality files/rasps...u'll get the desired thickness and the material is pretty decent...

: just dont see the point in polishing any blade other than the ones made in stainless steel to a mirror finish as no matter what you do it going to rust n pitt sooner or later

...buddy, on the contrary, a mirror polish is more suited for non stainless steel.. besides the aesthetic value the polish removes micro pits/crevices and pores on the blade surface. These are the very places where moisture is retained and oxidation/rusting starts. A mirror polish on carbon steel will reduce moisture retention to a large extent and prevent rusting...anyway, regular tending of your blades to maintain that gleam and sharpness is a rewarding experience in itself...

[kshitij]

...buddy, on the contrary, a mirror polish is more suited for non stainless steel.. besides the aesthetic value the polish removes micro pits/crevices and pores on the blade surface. These are the very places where moisture is retained and oxidation/rusting starts. A mirror polish on carbon steel will reduce moisture retention to a large extent and prevent rusting...anyway, regular tending of your blades to maintain that gleam and sharpness is a rewarding experience in itself...

Never thought of that. Makes sense.

[aadhaulya]

Knife-Making
www.hansoncustomknives.com/Knifemaking101.html

Here’s an excerpt from the above article:

Foreword:
Knife-making like blacksmithing is 80% mind and 20% muscle. If you think you can make a knife you can, if you think you can’t make a knife YOU CAN’T.
HEAT TREATING AND TEMPERING:
Note that heat treating hardens the blade, tempering softens the blade and removes brittleness to the desired level. They are not one and the same. Once the blade is rough ground, heat the blade to just above the temperature that it goes non-magnetic. On some steels it is desirable to hold at this temperature for a few minutes.

Check http://www.principalmetals.com/ for proper time and temperatures. I like to hold the piece at temperature for about 5 minutes. I generally heat the piece to bright red, remove it from the forge and stamp my touch-mark into it, then return it to the forge and bring it back up to heat. Once the piece has reached the proper temperature, quench it in oil to cool.

Remember that it is not the destination that counts - it is the journey to get there. Enjoy the ride.
Briha

Briha ji,

Somehow I missed this wonderful article of yours. The tempering and hardening process was very interesting and informative.

Atul