Saturday, 2 November 2013

Field Cutlery, Part 1, or 2 Sort of, Two and a Half Inch with a Full Tang.

After knocking up those last thre knives in thin metal i was feeling confident about building a nice piece of field cutlery for myself, so i dug out a nice piece of hard steel i had forgotten i had lying about. It came off a frame with a gas strut the holds 85 Kg, and had varying lengths of 5 mm by 25 mm with the odd hole drilled in it which could be adapted into the design. It appeared to be hardened already as i couldn't scratch the metal but it wasn't, so i cut two lengths off with a disc cutter, and a steel cutting blade on a jigsaw which hardly dented it.

The jigsaw just didn't cut it.

Then i scratched a rough design into the black coating, one with a sub three inch blade edge and one a little longer.

Two bits of metal for two knives.

knife designed.

Once i was happy with the similar designs i set up the angle grinding disk in the Fonly lathe, using a piece of wood for support to set about getting the rough shape of the knife. The edge of the disk was ideal for cutting in to shape the tang and choil, and then round off any concave shapes.

Grinding away excess metal to shape the tang.

I used the face of the grinding disk to round off the drop point at the tip at the front, and any other convex or flat edge such as the tang.

Makes a nice 90 degree angle to the side of the blade.

Once i got the shape i desired using a metal file i removed any burrs around the edges, i already had a nice 90 degree edge by using the wood as a base to hold the knife side onto the disk face.

Removing any burrs.

I now needed to build a jig to support the knife at an angle so i could grind the blade face, a block of wood with a bolt head at one end and the tang clamped at the other works very well indeed.

By placing washers between the bolt head and wood i can increase the angle, it might also be a good idea to glue the wet and dry on to the disk.

The blade edge is flush with the top of the wood and clamped in place.

To make sure the blade edge was even and straight i first covered the edge with nail varnish, then scored along the edge with the point of a wood drill bit the same width as the metal so the line ran along the middle.

The scored line in the varnish gives me a true even straight line to grind down to.

I removed the metal using the flat edge of the grinding disk, though a belt sander would do the job a hell of a lot quicker but i don't own one. So i'll make do with this method, it's still quicker and o lot neater than doing it all by hand files

Start grinding the first side.

Flip the knife around to grind the other side, see how the first side is nice and straight.

I then finished off with coarse wet and dry on a disk sander, adding a disk of aluminium to the disk sander gave me a more rigid surface to work the bade against.

Finish off with the wet and dry gives a nice shine.

aluminium plate adds rigidity to the sanding disk.

 i left 0,5 mm along the cutting edge so as to have space to sharpen a cutting edge later on, there is also less chance of any damage being done when it gets heated when hardening the blade.  As you can see there is another knife on the go and i want to make a couple more before i harden and temper them, so i will leave this as part one or maybe part two of the the knife blog and come back with more when i've had the time to do the work. 

Any way more pictures of the process and of my work bench not looking totally cluttered for a change.

Pretty knife.

Wet and dry on a firm background.

Knife starting to look sexy in front of grinding gear.

same as before, same again.

More useful shit that can be used fore making knives and air rifles

 Mmmmmm, shiny knife and some grease i use on drill bits to help them cut better

Two knives, more to make as it would be prudent to temper them in larger numbers if i use the oven method.

Is it not a good start, i think so my friends. However i now need to go out busking so i can get a nice AA S410 with a Bushnell scope and moderator.


Best regards, Wing Commander Sir Nigel Tetlington-Smythe.

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