Here’s how to make a hook knife in about an hour – for use in spoon- and bowl-carving.
The hook knife is an important, but often overlooked, tool of outdoor life, rounding out the Bushcraft Quartet (to include knife, axe, and saw) quite nicely. Given these four tools, the accomplished outdoorsperson can make virtually every other tool and item needed for wilderness living. The four tools and their general uses/advantages are:
- Knife – Cutting stuff, like rope, as well as wood-carving and fire prep work
- Axe – Heavier woodwork, felling and processing trees/firewood
- Saw – Arguably the most limited of the lot. Primary advantage is clean, straight cuts (as opposed to cuts made with the axe) while using less energy (i.e. calories) than the axe
- Hook Knife – Carving concave shapes, such as spoons, bowls, and other containers. Particularly useful when one needs water-bearing containers made of wood. (Try doing that with a standard fixed-blade knife!)
In this article, I’m going to walk you through making your own hook knife using materials you (or your neighbor) probably have laying around. After you’re finished, check out our other blog (and free instructional video) on putting it to use to carve yourself a spoon.
1. Prepping Your Work Area and Materials
I love to make hook knives out of old, worn-out reciprocating saw (‘Sawzall’) blades. They’re already thin, so stock removal is a breeze when sharpening. It also re-purposes a material that would otherwise go to waste. And if you know someone with a reciprocating saw, they tend to have plenty of old, dull blades – which means your knife stock is free!
Are you sans-reciprocating saw? Use what you have: old files, putty knives, or any steel that somewhat resembles the size stock you see in the photos. The better-quality your steel, the better the end result. However, we’re making a quick and dirty hook knife, so I like to use whatever’s laying around.
Depending on the length of the blade you’ll want to shorten it. I’m beginning with a wood-cutting sawzall blade of about 8″.
Begin by cutting the blade to a length of about 4″ using a hacksaw. (Or clamp the blade in a vice or pliers and bend back & forth until it breaks.)
Grind the teeth off the basal half in order to retain the tang and have uniform width throughout the length of the knife.
Note: You’ll often see hook knives with tapered blade, such as this one made by Swedish company Mora. You can use the tapered section of the sawzall blade to make such a hook knife.
2. Sharpening The Hook Knife
I prefer a double-edged hook knife (so it can be pushed or pulled and left- or right-handed), but you’ll also see single-edged knives.
Draw a line down the middle of one face of the stock with a Sharpie, as shown. Clamp your prepared stock to a solid surface. Imagine a low angle running from each edge to the centerline. That’s the angle at which you’ll want to hold your file for this next step.
Using a mill bastard file, file from one edge (then the other) to create a dual-beveled blade. You can remove a lot of material and make the knife rather sharp with just a file, but you can also continue with coarse/medium/fine stones and a hone if you wish. You can see the progression of the filing/sharpening below. The line acts as the ‘ridge’, the thickest part of the knife. The blade should grow continually thicker from each edge to the line.
Note: If you plan to harden and temper your blade, be cautious about making the edge too thin. If a hot piece of metal is quenched (cooled) too quickly it can crack. That risk is magnified in a very thin blade. If you plan to harden/temper, just get rid of the 1/16″ or so edge of the sawzall blade (so it doesn’t reflect light) but don’t worry about getting it wicked sharp. You can do that on a stone later.
3. Bending The Hook Knife With a Heat Source
Here comes the fun part. You’ll want a propane torch (or other heat source), pliers, heavy leather gloves, and a nonflammable object to bend the blade around. About 1 1/2″ diameter is a good size.
Heat the sharpened blade by moving the torch around. The thin parts will heat very quickly, so favor the thicker part of the blade with the flame.
Heat the blade to an orange-red color then quickly set aside the torch and bend the blade around your form. Hold it there for a few seconds until the orange-red color fades.
Heat the blade to orange-red again, isolating the flame to the section pictured, where you’ll bend a sharp ‘dog-leg’. You can simply use two pairs of pliers to make this bend.
If you wish to re-temper the blade, do so now. Tempering is a science unto itself, but in a nutshell: heat the blade to glowing then quench (rapidly cool) the blade. Water can be used, but there is significant risk of cracking the blade by cooling too rapidly. A safer option is to use a non-flammable oil (such as vegetable oil) to quench.
I moonlight as Captain Hook.
4. Carving The Proper Hook Knife Handle
Carve a wooden handle to suit. Note that a handle with an elliptical cross section will not only be more comfortable than a round one but will give a natural feel to the front-back axis of your knife without thinking about it.
Drill any holes necessary for attaching the blade, using nuts/bolts or metal pins. Attach the blade — and go let those shavings fly!
Be sure to check out our other blog and video on carving a spoon using your new hook knife!