If you’re interested in making a knife but don’t have access to a metal forge, an angle grinder can help you get started. It’s also a great tool for sharpening tools like garden spades that often have a blunt edge after using them all season.
Start by using a coarse belt (P180 to P220) and chasing the bevel line with it, gradually increasing the pressure and grit as you go. This will create the initial bevel and help your blade meet the scribed line on the blank’s edge.
Blade Design
When you use an angle grinder for knifemaking, it is important to design a blade that is suited to the task at hand. The blade should be strong enough to withstand the rigors of use and be sharp enough to cut effectively.
Fortunately, there are many different blades available for use with an angle grinder. There are some that will only cut metal, while others are specialized for cutting materials like wood.
The best angle grinder blades will have the right abrasion resistance and cut-off diameter to handle all types of materials. They are also designed to be safe for use with high speeds, which are often necessary when making knives.
When you use an angle grinder to shape the blade, it is a good idea to have a variety of files to help you smooth out the lines and round out corners. Using various sizes and shapes of files will make the job much easier.
Stock Removal
Knife making is a growing interest amongst a wide variety of people. There are two fundamental ways to create a knife, the first is called forging and this involves heat treating and hammering the steel into shape until it is knife shaped.
Stock removal is more common and this involves using saws, belt sanders and other abrasives to strip material away from the workpiece until you have created a blade. This is a much more efficient process than forging and it is also less expensive.
A typical knife maker will use a number of different tools for this stage: hand files, a band saw or even a flap disc on an angle grinder. Once the blade shape is defined it is then refined by grinding, filing and sanding with different grits.
The blade is then heat treated, quenched and tempered to harden the steel. This can be done with a forge or a kiln. Some steel suppliers offer this service at a reasonable cost.
Belt Grinding
When making knives with an angle grinder, it’s important to know how to properly use a belt grinder. This will ensure that you get the best results possible when shaping the bevel of your knife’s blade.
To achieve the desired bevel, you need to secure the blade into a bevel jig and slide it along the belt’s work table while applying steady pressure down and inward towards the belt. This will keep the curved belly of the blade consistently in contact with the belt as it grinds the bevel to a point.
Once the bevel has been shaped, it will need to be ground down and polished. This is done by progressively finer grits on the belt until you reach the finish you want.
Heat Treatment
After your blade has been forged, it’s time to heat it up to harden it. This can be done over a fire, with a blowtorch or a kitchen oven, but if you’re using the latter, be sure to let it cool between each cycle.
Once you’ve tempered the blade to a suitable hardness, it’s ready for final sharpening and polishing. You can use abrasives to achieve this, but you might want to use something that’s designed specifically for the job.
If you’re a knifemaker, you can find a variety of abrasives at your local hardware store. You’ll also need a belt sander and a sharpening stone.
If you plan to make a lot of knives, you may want to consider getting a heat treating oven or kiln. This will allow you to control the temperatures and soaking times required for optimal hardness and toughness.