Throwing Knife

by mandamados

24K53121

Intro: Throwing Knife

Overall Length: 25 cm

Blade Thickness: 4.2 mm

Blade Material: Uddeholm arne steel

STEP 1: Profiling the Knife Shape

Profiling the knife shape with an angle grinder. Use drill grinding wheels to profile the curves of the knife.

STEP 2: Grinding

used Uddeholm Arne tool steel, 6mm thick. But the knife should be about 4 mm thick, so it should be ground. Use a dust mask for safety.

STEP 3: Drilling

At this step i made holes at the handle and then rounded the edges

STEP 4: Final Step

Now its ready for hardening and tempering

20 Comments

BMXfreestyler112_ 6 years ago

hi! I currently work at a steel company!! and use metals every day! I tried to make one with a grinder but its shape and sharpness were insufficient to my standards! but ill try again

spiffysquirrel 7 years ago

You probably could if it was a circular saw blade, but you would need to make sure you don't heat it up while cutting it out because it would damage the heat treatment unless you know what type of steel it is to heat treat it. Though it may need a little bit of tempering if it was only hardened.

backwoods boy 7 years ago

thank you great instructable btw keen to try and make it

dkmd0824 8 years ago

How did you figure the balance point of the knife when making it?

ToolboxGuy 8 years ago

I would draw out a template, choose my balance point and draw a line on the template. Then trace the template onto graph paper, marking my balance point. Count up the squares on each side of your balancing line for a rough answer. If you have a good idea as to the blade profiling, you can colorize the drawing with the estimated thickness along each side, then count those as half squares instead. Otherwise, you could always oversize the handle and trim away until you get balance or simply enlarge the holes to drop weight from the handle. Best to finish blade profile before looking to balance. Some prefer heavy handles and other prefer heavy blades. Enjoy your creations!

gumby_kevbo 8 years ago

Just counting squares doesn't work. The squares near the balance point have little effect, the ones far from the balance point have large effect. So count the first row from the balance line, and multiply by 1, multiply the second row by 2, third row by 3, etc. The mass x distance is called the moment. This is how the CG of an aircraft is calculated, for example.

If you use your initial guess as the point of the knife, and add up all the moments, you can then divide by the total number of squares, and this will give you the location of the balance point as distance from the tip. If you initially guess in the middle, then you have to keep track of positives and negatives, so it is less error prone to start at one end and work from there.

Honestly it will be easier to to cut it out of cardboard and see where it balances.

glorybe 8 years ago

Please be very careful. My state considers any two edged blade as an illegal weapon and possession is a felony. These days even a misdemeanor conviction can ruin any chance of employment for the rest of your life. The laws are absurd. Just don't let them swallow you alive.

xarlock667 8 years ago

It is not illegal to own, it is illegal to carry. A silencer for example is illegal to own without a permit, doesn't matter if it is in a safe, or in your vehicle, it is illegal anywhere in the US, this knife however is illegal only if you are carrying it on your person, not at a range or other legalish area (Dojo for example). Leave it at home, and you are ok.

Steelsmith1 8 years ago

Silencers are illegal in some states. Here in Arkansas anybody who can legally possess a firearm can legally possess a silencer, or suppressor. However, you must comply with buying a tax stamp for it and comply with storage of it. Federally they are legal but state laws vary. I have a friend who sells legal silencers.

ToolboxGuy 8 years ago

Wow! If that grinding wheel used wasn't dull already, it is well worn by this work! How long did it take to grind away this much metal?

acoleman3 8 years ago

love it! the size, shape, your technique is simple and you actually used something worthwhile as your material. too many times i've seen diy tutorials where they use a mild steel and then expect it to actually harden when they heat treat it. that blade looks like it'd be fun to throw hahaha.

acoleman3 8 years ago

no, it's not too big. i've seen knives that size and larger at throwing competitions before. really, the smaller ones are harder to throw because of their little mass and the fact that they spin more when you throw them.

kwknowles 8 years ago

In my experience, bigger knives are easier to throw, even though they can't be thrown as hard. Great for learning.

mandamados 8 years ago

Yes it' s big but it' s my first throwing knife. The ideal length it was 16 cm

Edbed 8 years ago

Great instructable!