How To Make a Cheap, good quality Shuriken throwing star

Intro : Cheap, good quality Shuriken throwing star

I've searched and searched, but no where could I find instructions on how to make a nice, high quality, amateur throwing star. In this instructable, I will guide you through the process of making a steel shuriken for under 10$ (if you already have the tools).

DISCLAIMER: This is a WEAPON and is not for just throwing around at people, pets etc. It can SERIOUSLY injure or even KILL somebody. The blades are extremely SHARP. I am not responsible for anything that you do with this. If you are foolish enough to throw it at a person or a pet then just stop reading now.
Have fun and BE SAFE!!

First Step : Getting the stuff

A minimum of what you need:
-A metal plate of some sort, relatively thick. It should be no larger than 5 inches or you will waste a lot of material. I used a galvanized steel electrical box cover I got from home depot for about $0.60. This works VERY well.
-An angle tool, or something that can measure and draw straight lines exactly perpendicular to the sides of the plate
-A pencil
-A jigsaw OR:
-A hacksaw with steel cutting blades (much slower and harder)
-If a jigsaw, high speed steel cutting blades. A pack of 3 cost me about 5 bucks.
-A bench grinder or equivalent (steel belt grinder, dremel, etc)
-3/8" steel drill bit. Mine was a zirconium coated bit from a big set my dad got. You could also buy a cobalt bit, but a 3/8" one would run you about $10. Ouch
-A drill that can run at least 800 RPM, hopefully with a lot of torque
-Metal file
-240 grit metal sanding sand paper (needed to make the pencil marks show up on the plate)

OPTIONAL:
-A drill press (I didn't have one so I was just careful. It isn't vital for the holes to be that precise)
-Some silicon carbide metal sandpaper (60, 120, 240, and if you want it really smooth, 400 and/or even 600 grit paper. Whatever you want to do.

Step 2 : Prepping the plate

In order to draw on the plate with pencil, it needs a rougher texture than the glass smooth-ness that it comes with. You only need to prep one side.
Start with 60 grit silicon carbide sandpaper if the metal has lots of bumps. If not just use 240 and sand in small circles until the whole thing is done. You should be able to make a mark with your pencil.

Step 3 : Drawing the base square

Find two touching sides that are perfectly flat. If all of them are flat, then just pick a top and a side and scribble close to the very edge. Only put the flat of the right angle tool on these sides and only measure from these two sides. Now measure and draw a 2 1/2 inch square in the very center of the plate. For example, on my 4 inch plate, I had to measure in 3/4 of an inch in from the edge and drew a line. Then I measured 2 1/2 inches farther and drew a line there. So now I have 2 parallel lines that are 2 1/2 inches apart. Repeat this in the other direction and you will have a perfect square. Now, find the midpoint of each side of the square and mark them. Now draw a straight line between them. You should now have 4 small squares. The picture can better show what I mean.

Step 4 : Drawing the star

From each midpoint, measure 3/8" straight in and mark there. These are the inside points of the star. From there, draw a line from the two nearest points of the square to the newly marked spot. Repeat this 4 times on each side. You should now have a basic star shape. See the picture if you don't quite get it.

Step 5 : Drilling the holes (optional but looks way cooler)

Now if you have a drill press, this step will be a breeze. If not, then, like me, you just have to be careful. You are going to be drilling at inside star points. It's kind of hard to explain, so look at the image for reference. You are going to use the 3/8" drill bit for these holes. If you don't have a drill press, it would probably be easier if you use a bit about half the size to drill a hole first. It's hard to get a big bit to go exactly where you want in one shot. You can be more precise with smaller bits. Also, if you want to counter any wind blowing it off target, drill a hole in the center.

Step 6 : Cutting it out

Now it's time to cut the thing out. If you have a jigsaw and you drilled the holes, start from the inside of the holes and go out. If you didn't drill the holes, then you just have to start from the outside. If you don't have a jigsaw, then don't bother trying to start from the inside of the holes. You need to clamp the plate down, I shouldn't need to explain the reason for that.
(The ideal tool for this step would be a bandsaw, but most people don't have one of those, and they're pretty expensive. However, you could go down to your local machine shop and see if they'll cut it out for you)

Step 7 : Cleaning it up

Now you need to clean up the edges of the star, since they will probably be pretty rough. So, using the grinder, flatten the edges up, or use a file, which will take a lot longer.

Step 8 : Sharpening

This step is semi-optional, but I would recommend it. Now that your sides are flat, use the grinder (or a file) and grind edges onto the star. They should be at about a 45 degree angle. When you finish grinding an edge with the grinder, quench it in some water and slosh it around to cool it off (its SUPER hot).

Last Step : Finish!

Now your star is complete! If you want, you can make the edges razor sharp with a fine file, or whatever, but remember this isn't super high quality steel, so it probably won't hold an edge for long.
Now remember, Have Fun but BE SAFE!!!

source : instructables.com