Throwing knives have an edge similar to an ax. A throwing knife is a ranged weapon designed to disable an opponent long enough for you to draw a more effective, close-range weapon, or to deter an opponent from approaching closer. Making knives of any kind can be very hazardous.
This article assumes that the reader is an experienced metalworker. This article also assumes that you have access to a fully equipped metalworking shop and have knowledge of the correct and safe usage of power tools, including grinders and abrasive saws; working knowledge of metalworking techniques and terminology; and understand the correct use of safety equipment, including National Institute for Occupational Safety and Health-approved respirators, wraparound eye protection, and ear protection.
Things You'll Need
- Wraparound eye protection
- Ear protection
- NIOSH-approved respirator
- Bench grinder
- Right angle grinder with abrasive saw
- 1 piece of suitable, hardened, high-carbon spring steel, such as a lawn-mower blade, large circular-saw blade or power-hacksaw blade
- Wire wheel for bench grinder
- Grinding wheel
- Coffee can full of water
- Black marker
Place your chosen piece of high-carbon spring steel in your kitchen oven. Bake steel at 550 degrees Fahrenheit for one hour. Allow to cool to room temperature in the oven. Repeat this step three times, allowing the steel to cool to room temperature between each heating and after the final heating. This is known as triple drawing or triple tempering. This reduces the brittleness of the steel to make a more durable blade.
Shine the steel with a wire wheel to remove any blue color. Use a permanent marker to lay out the desired throwing knife profile on the steel. Use an abrasive saw to rough cut the blade profile. Use a bench grinder to smooth the profile of your throwing knife, removing any burrs. Make sure to keep the steel cool with water while grinding. Do not allow the steel to change color.
Grind bevels on all four sides of the throwing knife blade. Bevels should be no less than a 25 degree included angle between the front and back of the knife. Again, be sure to keep steel cool with water while grinding and do not allow any color change in the steel.
Finish your throwing knife with 80- and 120-grit abrasives on all surfaces. Use a wire wheel to give your knife a satin finish.
Sharpen your knife as desired. Remember that a throwing knife has a steeper edge angle and is not usually kept razor sharp. This is especially important if you will be throwing at live targets, as for a circus or fair. A throwing knife will usually have an edge similar to an ax.