How to choose a survival knife

Out in the woods with little else, a steel blade is the tool that makes most of the other tools. It shapes stakes and trap parts, splits kindling, carves the notch in a fire board, cleans fish and cuts cordage. A blade can be knapped from stone or ground from bone in a pinch, and people have lived that way for a long time, but nothing improvised comes close to steel for strength and edge.

Not every steel knife is suited to that work. Plenty of blades that look rugged in a catalog fail at the first heavy job. The good news is that the features separating a dependable survival knife from a poor one are easy to learn and mostly visible before you buy.

Things to avoid

A narrow tang

The tang is the part of the blade that continues back into the handle. Pull the handle scales off a cheap knife and you often find a thin rat-tail of steel, sometimes threaded into a pommel nut. That is fine for slicing vegetables. It is a weak point when the knife is used to chop, to pry, or to split wood by striking the spine with a stick, and that is where these knives tend to snap.

Folding knives and multi-tools

A folding knife in the pocket is useful every day, and a folder handles most small camp jobs well. It is still a compromise. The pivot and lock are the weak spots, and hard work loosens them. If the question is what the ideal survival knife looks like, a folder is not the answer, even if it is the knife most people will actually have on them.

Very large knives

Films have given many people the idea that a survival knife should be as long as a forearm. Size helps with chopping, but it makes fine work clumsy, and fine work is most of what a survival situation asks for: carving trap triggers, shaping spindles, making feather sticks, preparing game. A long blade is also heavier to carry and harder to control.

Hollow-handled knives

The classic hollow handle with a tiny kit inside the cap is usually two pieces of metal joined at the guard. That joint is exactly where it breaks under a baton. A handful of makers build one-piece hollow-handle knives that hold up, but most on the market are closer to novelties than tools.

What to look for

Full tang

This is the single most important feature. On a full-tang knife the handle is simply the tang itself, the same width as the handle outline, with scales of wood, micarta or synthetic material riveted or screwed to either side. Blade and handle are one continuous piece of steel, so there is no joint to fail.

Fixed blade

Nothing folds, nothing locks and nothing needs to be kept free of grit. A fixed blade can take the strain of batoning and prying that would ruin a pivot.

A sensible size

A blade of roughly 4 to 6 inches suits most people. That is short enough for delicate carving and long enough to split wrist-thick wood by batoning. Where you fall in that range depends on your hands and what you expect to do most. If you can, handle several knives before you buy; friends’ knives and outdoor shops are good places to learn what feels right.

Beyond those three basics, four more properties are worth understanding.

Steel type

Steel decides how strong the blade is, how well it takes a blow without chipping or breaking (toughness), how easily it sharpens and how long it holds an edge. Knife steels fall into two broad families.

Carbon steels take a very keen edge, tend to be tougher under chopping and splitting, and are easy to sharpen on a simple stone in the field. Their weakness is rust. A carbon blade needs to be dried and lightly oiled, and it will stain with use.

Stainless steels resist rust far better. Cheap stainless can be brittle and hard to sharpen, but in good knives from careful makers those differences shrink a great deal, and the choice comes down to maintenance and preference.

Stainless steels with good reputations for outdoor knives include:

• CPM S30V
• CPM 154
• BG-42
• S60V
• S90V (very hard wearing, but slow to sharpen by hand)

Carbon and tool steels with good reputations include:

• A2
• Carbon V
• 1095
• O1

Lists like this one often file CPM 154 under carbon steels by mistake. It is a stainless steel, a powder-metal version of 154CM.

Blade shape

The outline of a blade decides what it is good at. A chef’s knife is shaped for slicing on a board and has no business splitting wood. Double-edged spear points and chisel-tipped tanto blades are built for piercing, and their tips are awkward for carving and weak for prying.

The two outlines that suit outdoor work are the clip point and the drop point.

A clip point has a concave curve cut into the back of the blade near the tip, which makes a fine point. A modest clip is strong enough for field use. A deep, exaggerated clip leaves a thin tip that can break when the spine is struck during batoning.

A drop point is the better all-rounder. The back of the blade slopes gently down from about halfway along and meets the edge a little above the centerline. The result is a strong tip, a long belly for slicing and skinning, and enough control for carving.

The edge

The cutting edge should run in one continuous plain curve from the handle to the point. Serrations cut rope and seatbelt webbing quickly, but they are hard to sharpen in the field and add little for camp work. A partly serrated blade also loses the stretch of plain edge nearest the handle, which is the part used most for controlled carving.

The spine

The back of the blade should be flat and square, without saw teeth or a false edge. A flat spine is the striking surface when you drive the knife through a log with a wooden baton, and a square edge on it will throw sparks from a ferrocerium rod. Some well-known designs add a saw section to the spine and do well at chopping and notching, but they are heavier and more specialized.

Handle and sheath

A handle should fill the hand without hot spots and stay secure when wet, cold or greasy. Micarta, textured synthetics and stabilized wood all grip well; smooth polished handles and bare metal do not. A modest guard or a finger choil keeps the hand from sliding forward onto the edge during hard pushes.

The sheath matters as much as the knife, because a knife that falls out on the trail is lost. Look for one that holds the blade firmly without a strap, covers the edge fully so it cannot cut through, and drains water. Leather looks good and stays quiet; plastic and nylon sheaths shrug off rain and need less care.

Using it safely

Baton only with a full-tang fixed blade, and strike the spine with wood, never with a rock or a hammer. Cut away from your body and keep the other hand behind the edge. A dull knife slips, so carry a small stone and touch up the edge often.

Carry laws for fixed blades differ from state to state and city to city. Check them before a knife goes on your belt anywhere other than the trail.

Finding the right one

Everything above describes the ideal. The knife that actually serves you is the one that fits your hand, suits the country you travel in and gets used often enough that you know it well. Borrow knives, try them on real tasks, and take note of which size and shape you keep reaching for. Then buy the best-made version of that knife you can afford.