On this page
- Understanding Different Knife Grinds
- Laying Out Your Center Line
- Helpful Tools for Beginners
- Setting the Initial Edge
- Proper Body Mechanics for Grinding
- Belt Progression and Finishing
- Watch this lesson
Good day, everybody, and welcome back to Sword Wolf Forge. This is Lesson 6 in our Bladesmithing 101 series. If you have been following along, we have designed our blade, cut it out, and ensured it is properly heat-treated. Today, we are ready to proceed with grinding the bevels.
There is a lot more to grinding a bevel than just simply stepping up to a grinder. You must consider edge geometry, prepare your guidelines, and learn the correct body mechanics before making your first spark. Grinding features a very slow and painful learning curve at first. However, if you stick to it and build that muscle memory, you will get it eventually. Let's jump in.
Understanding Different Knife Grinds
Before we start grinding, it is crucial to understand edge geometry, which refers to the angles of your blade and how much material supports the cutting edge. The geometry you choose directly affects the knife's cutting abilities.
- Flat Grind: This grind is flat on each side and comes straight to a point with no secondary bevels. It is exceptionally thin and great for slicing, making it very common on kitchen knives. However, there is not a lot of meat behind the cutting edge for heavy-duty tasks.
- Scandi / Saber Grind: These grinds have a steeper angle that only takes up a percentage of the blade, leaving a lot of robust metal supporting the edge. You will commonly see these on bushcraft knives and fighting knives like the Ka-Bar.
- Hollow Grind: Usually featuring a secondary bevel, this concave grind slices efficiently because material does not stick to the blade, and it significantly lightens the knife. Typically seen on Bowie knives, it is more complicated to execute and requires a grinding wheel.
- Convex / Acorn Grind: This grind features a massive amount of metal supporting the edge. It is not meant for slicing tomatoes, but rather for pushing material away, making it the standard grind for splitting axes and hatchets.
- Chisel Grind: Ground on only one side with nothing on the other, this is used for standard chisels and certain Japanese cooking knives.
- Compound Grind: This grind takes the best of both worlds, often taking a flat or Scandi grind and adding a secondary bevel to keep the edge better supported and robust.
For our beginner knife today, we are going to use a compound flat grind. We will bring the main flat bevels all the way to the spine and put a secondary bevel on the edge for robust support. A flat grind is the easiest all-around grind to execute, setting you up for success rather than failure.
Laying Out Your Center Line
Before grinding, you absolutely must find your center line so you know exactly where to grind and ensure your bevels are perfectly centered. If you skip this, you run the massive risk of having your cutting edge skewed entirely to one side.
Clean up your blade and apply a coat of layout fluid or a black Sharpie along the cutting edge. You do not need expensive scribing tools or complex math to mark the center. Since we used 3/16-inch thick steel to cut out this blade, simply grab a 3/16-inch drill bit. Lay the drill bit completely flat on a level table—do not use a soft wood table for this—and drag the point of the bit against the dyed edge of your blade. Flip the blade over and drag it again. The point of the bit will scribe a perfect, visible center line in the layout fluid, giving you a safe boundary to grind toward.
Helpful Tools for Beginners
- Knife File Guide: This tool clamps directly onto your blade and features plates made of carbide, which sandpaper, files, and grinding belts cannot cut into. You attach it prior to grinding to establish exactly where you want your bevels to terminate near the handle. It keeps your plunge lines uniform on both sides and prevents you from grinding too far back. I still use this incredibly helpful tool today.
- Knife Grinding Jig: A jig firmly clamps your blade and slides along a 90-degree work rest, keeping the blade stable against the platen. It takes the freehand guesswork out of the process, helping beginners learn to move straight back and forth to create consistent lines without waves. You set the proper angle by coloring the blade with a Sharpie, making a light pass, and adjusting the jig's screws until the belt contacts the steel perfectly. However, it is difficult to navigate the curve of the tip with a jig, and you cannot easily use a file guide at the same time. It is a great starting tool, but you eventually want to work towards freehand grinding without one.
Setting the Initial Edge
Always ensure you are wearing eye protection before making a single spark; getting metal in your eye is a terrible experience. Mount a fresh, aggressive 36 grit belt on your grinder.
Before you start sweeping your main bevels up the face of the blade, you want to grind aggressively at a 45-degree angle directly down to those scribed center marks. Doing this establishes a thick cutting edge right away. This heavy 45-degree chamfer gives you a visual reference while grinding the rest of the bevel, preventing you from accidentally grinding straight through the center and ruining the knife.
Because this blade is already heat-treated, you must keep a bucket of water right next to your grinder. Make one or two quick passes on the belt and immediately dip the blade in the water to keep it cool. If you overheat the steel, you will burn out the temper and create a useless soft spot in your blade. Use bare hands instead of gloves so you can instantly feel how warm the knife is getting.
Proper Body Mechanics for Grinding
When grinding, do not muscle the blade or jam it into the belt. Use finesse, apply steady pressure with your thumb behind the belt, and steer with your off-hand.
The biggest key to smooth, wave-free bevels is ensuring the blade stays perfectly horizontal to the platen at the point of contact. Stand squared up facing the grinder, keep your elbows tucked in close to your body, and sway back and forth using your entire body rather than just swinging your arms. If you cock the blade at weird angles or pull away from the platen, you will create massive gouges.
When you drag the blade across the flat section, simply follow the horizontal line. As you reach the curve of the tip, you must carefully lift the handle to turn the edge upward, maintaining that exact perpendicular contact with the platen. Because this takes an immense amount of practice, I highly suggest practicing these mechanics on cheap, low-carbon scrap steel or even wood before risking your newly heat-treated blade.
Belt Progression and Finishing
Once your initial 36 grit bevels are pushed all the way up to the spine, and that 45-degree edge is almost gone, you know your bevel is beautifully centered. Now it is time to refine the surface by stepping up your belts.
Move to a 60 grit belt to thin the cutting edge down further and clean up the deep, rough scratches. Next, switch to a TriZact A65 belt, which is roughly equivalent to a 120 grit. Let this fine belt hang slightly over the edge of the platen so you can gently work into your plunge lines, softening and blending them evenly. While working on this stage, carefully run the 90-degree top spine of the blade across the belt to soften those harsh edges so they do not cut the user's hand. Finish up the grinding phase with an ultra-fine TriZact A300 belt to leave a highly refined surface.
You do not need an expensive 2x72 machine to accomplish this; budget-friendly 1x30 or 2x42 grinders from Harbor Freight or Grizzly will absolutely get the job done.
We now have a clean, centered knife with excellent plunge lines. In our next video, we will focus on hand sanding and putting a proper finish on the steel. Stay sharp, everybody.
To follow along with the full series and see these builds in action, subscribe to our YouTube channel.
