Article completely revised November 2015
Related article: Sharpening your knife
Warning — Familiarize yourself with local laws concerning the possession and use of knives and machetes.
The survival knife
A knife is an indispensable survival item. It helps you build a shelter, start a fire, cut rope, prepare food and countless other tasks, but a knife can also be an effective weapon for both hunting and self–defence. Illustrated in the photo (left) is an MK3 knife by Doug Ritter, which meets all the requirements of a first–class fixed blade survival knife.
Other excellent survival knives
Beware of counterfeit copies of top quality knives made in China. The market is currently flooded with them.
What exactly is, a "survival knife?"
A survival knife is a knife that can be used for a multitude of purposes in a survival situation, so it must be light, safe to handle and very strong. It has to keep a 25° – 30° sharp edge and the handle and blade must be unbreakable. A sheath knife (fixed blade) is usually the best. Carry a folding knife as a spare and it is advisable to always have two knives with you. A folding knife is not as strong as a sheath knife because it has several moving parts and is best sharpened with a 20 – 25° edge and kept for lighter work such as slicing or skinning.
Physical characteristics of a survival knife
Length and strength
A survival knife does not have to have a long blade; the best length is around 10 – 15 cm (4 – 6 inches) long, with the thickest part of the blade being between 4 – 6.5 mm (0.16 – 0.26 inches) thick. Longer knives are cumbersome to carry and the risk of accidents when using them in a tired state is considerably higher. If a longer blade is needed, it is better to carry a machete, kukris or axe. The blade should not be flexible but neither should it be too thick because thick blades cannot do the finer work a survival knife is often required to do. This blade used for chopping and a best sharpened at a 35° to 40°angle
Knife blade shapes
Construction of a blade
The tang of the knife or machete (part that fits into the handle) has to be strong and this is something to look out for when buying your knife. Most knives or machetes fail at the tang or at the point, and a survival knife or machete blade and tang should all be made out of one piece of steel as illustrated in the above photo.
To reduce the weight of the knife and cheapen production, some makers cut away the tang. When you look at the knife handle from the side it looks as if the blade and tang are one solid piece and the tang is sandwiched in the handle. If you removed the handle, you would find the tang is cut away inside (photo below).
A half tang blade is cut away, fixing into the centre or top of the handle, as shown in the photo below. Knives constructed in this way are not strong enough to use as survival knives.
Ask how the knife is made when you buy it. If the seller is unsure, go somewhere else. Cheap survival knives are often made so that the metal blade is separate from the handle. The weak point on these badly made knives is where the blade and handle are welded, bolted or even glued together. A cheap knife may have a short tang moulded into a plastic or rubber handle; these knives are not suitable as survival knives. You would do well to avoid such a cheap knife in favour of the superior full tang or narrow tang models where the blade and tang are all made out of one piece of steel without welds.
Avoid "novelty" survival knives with hollow handles filled with "survival equipment" such as compass, fishing gear, etc. (See photo, below.) Even if this survival equipment is high quality (frequently not so) the hollow handle seriously weakens your knife. If you lose your knife (heaven forbid), you have lost some, or all, of your precious survival equipment as well.
A compass attached to a knife is a bad idea because steel becomes magnetised and will affect the compass's accuracy. Keep away from all these gimmicks.
A thick, wide, sturdy point is best for survival use. A drop point blade (such as the RSK MK3) is typically best, although some clip points (see photo right) are acceptable. If you look at a clip point blade, you will see it reduces blade strength near the point.
A straight blade edge is usually the best for survival use. A serrated blade is more difficult to sharpen and it is better to use a Commando saw or hacksaw blade if you need to saw something. Chose a single–edge blade because a double–edge blade is not as safe to handle and it is illegal to carry one in many countries. Straight, single–edge blades are useful for carving, chopping and cutting. Though they may not cut through materials as efficiently as a serrated blade, straight bladed knives will still do a good job. A compromise is a blade which is part serrated, such as the ESSE Survival Knife as shown below.
The added advantage of the straight blade is that you can sharpen your survival knife using natural materials should you not have a regular sharpening stone handy, whereas the serrated blade generally needs a special sharpening device and technique.
It is important that the tip of the knife maintains its strength as this is an area where the knife is likely to fail. Do not be tempted to change the shape of your knife by grinding down the end to make a longer, narrower point.
Stainless steel and carbon steel are used for making top quality survival knives. Stainless steel knife blades are rust resistant and this is vital if you are venturing into wet environments such as tropical areas. Stainless steel knives require less maintenance than carbon steel knives. They tend to be more expensive, are more difficult to sharpen and may not hold an edge as well as carbon steel, but stainless steel is the best all–round material for a survival knife.
Carbon Steel knife blades will rust if not used regularly unless they are coated with a protective layer. They tend to hold their edge better than stainless steel knives. It is a matter of personal choice, I would always choose a stainless steel knife as this copes with the harshest working environments.
The handle of the knife has two uses — to ensure a firm and comfortable grip and to enhance or act as the finger guard to stop the hand sliding down onto the blade. Typical materials used are wood, a high impact plastic or high density rubber. Nine times out of ten, a survival knife ends up as a chopping tool at some point in its history. Take this into account. A beautiful, polished, rosewood handle may look good but when you start whacking the knife around it may not last long if you miss the blade and hit the beginning of the tang. The handle must be unbreakable in extreme use and, therefore, much stronger than the handle of a general–purpose knife. These small details separate the survival knife from the everyday, run–of–the–mill sheath knife. Used carefully, a hardwood handle is fine and should take plenty of punishment but a tough composite material is better.
Look at the way the handle fixes to the tang as this a potential weak point. A variety of methods may be used — screws, rivets, moulded to the tang or a combination. Satisfy yourself that the fixing method used is durable.
The all metal knife is very strong but bear in mind that a metal handle has its drawbacks. It significantly increases the weight of the knife; it is impractical in very cold conditions because it will freeze to the skin or at the least become uncomfortable to hold for extended periods. Some people recommend wrapping a handle in Paracord or some other covering, never do this, as there is a risk the wrapping material will fail and you will harm yourself if the knife slips.
Which is the knife for you?
Buying a survival knife is an investment, and there is large choice. Bear in mind that a survival knife is stronger in construction than other knives and its concept is that of a general purpose knife. It is not designed to take a 20° edge, for this purpose you need to carry a folding lock knife or other smaller sharper knife. It is not designed as a hatchet or machete. In use, it falls between these two blades. It is important to buy the very best knife you can afford. It is also a good idea to get the feel of the knife before you buy it, go to a shop and have a look at several suitable knives, even mass–produced knives can fall out very differently.
Decide if you want a factory produced knife, or if your budget allows, consider a hand made knife; there are many excellent knife smiths around and generally, their knives are better made.
It is possible to buy a factory made knife that is not too expensive and there are many cheaper survival knives around that will give years of good service. The compromise on price usually means the knife is made from lower grade steel (hence more difficult to hone and maintain a sharp edge) and the handle is more likely to be high–impact plastic bonded to the tang. This makes it more difficult to know if the blade is full or half tang construction, which is why it is best to buy from a retailer who is knowledgeable about their products.
We are all different, and when choosing a knife find one that is easy to hold, has a good balance and it not too heavy. Bear in mind your local knife laws, and choose a blade that is not too long. A part serrated blade is useful if the serrated section does not fill more than one third of the blade length (remember you need a sharpener for the serrated edge).
All new survival knives come ground at 25° to 30° but they are not honed. So you will have to sharpen it. A good retailer can start you off by performing the initial honing for you, if they can't do that, go somewhere that can. After that, you will just have to touch up the edge with with a ceramic rod. If you want to learn how to re–profile and hone a blade yourself, see the section on Sharpening a knife
Getting the best out of your knife:
No discussion on survival knives would be complete without considering the folding knife. A folding pocket knife suitable for survival has a folding blade that is fully enclosed when folded/closed and is wider and stronger than a conventional pocket knife. It is possible to get blades that are part serrated. Knife laws still apply to folding knives and you must make sure of your countries laws before carrying one around with you. The UK and some other European countries have the strictest knife laws, for example, in the UK the knife has to be non–lockable in its open position, the blade has to be no more than 7.62 cm (3 inches) long, and it must only be opened by manually folding out the blade. Knives that can be flicked open with a thumb stud and spring loaded flick knives are illegal. Even if your folding knife conforms to the law, you still have to have a valid reason for carrying it on your person. The legal argument for not locking the blade in the fixed position is that it then becomes a fixed blade knife — you can make your own mind up on how sensible that law is!
Without doubt, a fixed blade knife makes the best survival knife, but there are advantages of also carrying a folding knife. It makes a good back up knife and because the blade is generally thinner, it can be honed to 20°'s, useful for finer work, filleting, slicing up meat and cutting material that the fixed blade survival knife would struggle with. It can be more easily concealed on the person if this is a requirement, and is smaller an lighter than a fixed blade knife. A smaller folding knife should be part of anyone's survival kit. If you honed the edge to 15°'s you could even shave with it.
Just as with fixed blade knives, there are many inferior knives for sale. These are made from inferior steel or alloy – such a blade is next to useless in any survival situation. Always buy a knife made by a good, tried and tested manufacturer who has a reputation to protect.
Top recommended folding knives
The Smith & Wesson 3rd Generation Black Ops M.A.G.I.C. Folder is a superb assisted opening mechanism knife that can take a razor sharp edge. (Not legal in all countries.)
The Gerber L.S.T. folding knife is ideal for packing in a survival tin. (Not legal in all countries.)
This knife designed and made by US knife maker Ken Onion is based on the Tanto blade style making it much stronger than a drop or clip point blade and an excellent survival knife.