Make a Knife
Making a knife from scratch can be a fun, rewarding, and useful metalworking project. It's time-consuming and work-intensive, but if you follow these steps you'll have a brand new knife before you know it.
Contents
Steps
Design the Blade
- Draw the blade. Use graph paper to design the shape of your blade. Try to keep it as close to actual size as possible to ease construction.
- Get creative with your blade design, but keep functionality and practicality in mind.
- Decide on blade length. The length of the blade is largely a personal preference, though large blades can be unwieldy and require lots of steel.
- Design the tang. The tang is the piece of the blade that attaches to the handle. The easiest method is known as the “full tang.” The tang will be the same thickness as the knife, and the handle is formed by attaching a piece of wood to each side with rivets.
Gather Tools and Materials
- Obtain carbon steel. There are many different kinds and grades of steel. Do not use stainless steel, as the metal is difficult to work with and the blade will not be as fine. 01 is a popular carbon steel for blade making because it is easy to douse when hot.
- Try to get a slab or bar between 1/8 to ¼ inch thick.
- Pick your handle material. Wood is an easy one to work with, though you can make a handle out of anything you would like. Since this guide is for a full tang knife, pick a material that you can attach with rivets. G10, micarta, and kirinite all are good choices and are waterproof.
- Trace your blade. Using a permanent marker, trace your blade onto the slab. This will be the guide you use when you cut the steel. Be sure to trace the tang as well, because the blade and tang are one connected piece.
- Make adjustments to the size as necessary once you see the outline on the metal.
- Assemble your tools. You will need a hacksaw, an angle grinder with a hard wheel and flap wheel, a vise, a drill, and protective wear also a few other tools you could have are bandsaw and a grizzly or KMG grinder. You will need several replacement blades for the saw.
Cut the Steel
- Use the hacksaw to cut the metal. Cut a rectangle around your traced blade to separate it from the main slab. You will need a stiffer hacksaw for thicker steel. This rectangle is what you will grind down to form the profile of the blade.
- Grind the profile. Put the rough cut blade into a vise and grind away excess metal. Follow the guidelines to form the profile. Use the grinder to finalize the shape of the blade.
- Grind the edge. Gently grind the edge into a slope with the flap wheel. Make sure that the slope does not go past the middle of the blade. Make this slope on each side of the blade. Doing this forms the actual edge of the blade.
- Go slowly during this step, as grinding too much can ruin the blade, forcing you to start over.
- Drill your rivet holes. Use a drill bit that is the same size as the rivets that you intend to use. Put the holes in the tang. Depending on the size of the blade, you may need a varying number of holes.
- Finish the blade. Sand the blade using successively finer grits of sandpaper, up to 220 grit. Be sure to take the time to sand out any scratches. Sand all areas of the blade. This will increase its luster and quality.
- Sand in opposite directions each time you change grits.
- You can use a file to add ridges to the inside near the handle. Trace a pattern and file the metal away.
Heat Treat the Blade
- Prepare the forge. The best way to heat treat a blade is using a forge. For smaller blades, a torch can work as a substitute. For a forge, either a coal or gas forge will work.
- Prepare your hardening bath. To cool the knife, you will need to douse it in a hardening bath. What you use depends on the type of steel, but for 01 you can use a bucket of motor oil. You need to be able to completely submerge the blade in the bucket.
- Heat the blade. Keep it heating until the metal is orange. Tap it against a magnet to see if it is hot enough. When the steel reaches the correct temperature, it loses its magnetic properties. Once it does not stick, let it cool by air. Repeat this process 3 times.
- On the 4th time, instead of letting it air cool, douse it in the oil bath. Be aware that there will be fire when the blade is put into the oil, so be sure that you are properly protected.
- When the blade is hardened, it can break when dropped, so handle carefully.
- Preheat your oven. Set your oven for 425°. Put the blade on the middle rack and cook it for 1 hour. Once that hour is up, heat treatment is complete.
- Sand the blade again. Use increasingly finer grits of paper, going past 220 and up to around 400 grit. Polish the blade if you want some extra shine.
Attach the Handle
- Cut out your handle pieces. For a full tang knife, there are two pieces of handle, one on each side. Cut and sand the pieces at the same time to ensure that both sides are symmetrical.
- Attach the pieces with epoxy. Drill the holes for the rivets on each side. Avoid getting epoxy on the blade, as it can be difficult to remove. Place it in a vise and let it dry overnight.
- Use a saw to perform the final cuts and adjustments to the handle. Insert the rivets, leaving about an extra 1/8” sticking out each side, and peen them with a ball-peen hammer. File the rivets down and sand the handle.
Sharpen the Blade
- Prepare the sharpening stone. You’ll need a large sharpening stone for these steps. Lightly coat the rough side of the stone with sharpening oil.
- Hold the blade at a 20° angle from the surface of the sharpening stone. Push the blade across the stone in a cutting motion. Raise the handle while moving the blade to sharpen all the way to the tip. After a few strokes, flip the blade over to the other side.
- After you have a sharp edge on every part of the blade, repeat the sharpening on the fine side of the sharpening stone.
- Test the blade. Hold a piece of printer paper in your hand and cut down near where you’re holding with the knife. A properly sharpened blade should be able to easily slice the paper into ribbons.
Warnings
- When working with knives, grinders, and saws, always exercise extreme caution and wear all the proper safety equipment.
Things You'll Need
- Graph paper
- Carbon steel
- Handle material (wood, bone, cord, etc.)
- Hacksaw with extra blades
- Angle grinder
- Vise
- Drill
- Forge or kiln
- Sandpaper
- Sharpening stone
- Sharpening oil
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