When seeking to buy a Survival Knife, here are the factors you need to consider to make the best choice.

Overall size, because size does matter.

The Tang.

Material of the blade.

The Handle.

Overall weight.

Design/Thickness of the blade.

The size of a survival knife is a very significant factor.

Will you be carrying it with you when you need it most? Most survival knives are 5 to 12 inches in length. Anything shorter and it just might not be large enough to the job. However if you don't have a part in the current Rambo movie, you probably don't need to go past 9 inches. Anything bigger than 9 inches or so and it starts to get encumbering to use and makes it more challenging to carry comfortably. You want an effective tool, not a weird limp. Will you be using it on camping trips to your fully accommodated cabin or are you expecting to make shelter when The End OF The World As We Know It (TEOTWAWKI) arrives? Clearly it can be smaller if your purpose is to whittle garden gnomes during your downtime at the cabin but ought to be on the bigger side if you plan on having a effective tool in any scenario you may find yourself in.

The tang is not that gritty orange powdered drink from the 70's. The tang is the protrusion of the steel of the blade into the handle of a knife.

Inexpensive knives will have a separate blade and handle instead of a tang. The most suitable survival knife will have what's called a full tang, where the blade extends in to the handle of the knife as close to the end of the knife as it can be. This is the logic to why you should not get a survival knife with a hollow handle to store matches or one that has a compass on the end of the handle. If the handle is hollow, then the tang isn't long enough to provide durability to the blade, or even worse there is no tang. My advice is to leave the compass, waterproof matches, fishing line and hooks in a separate bag and go with a solid handle and as close to a full tang as possible.

There are 2 main types of material used in the blade of a quality Survival Knife, stainless steel and carbon steel.

Stainless steel is great because it won't corrode easily when exposed to bad weather, is durable enough to take a shellacking and will generally last a long time. The downside to stainless steel is that the edge will lose its sharpness faster than carbon steel and requires proper sharpening more often. Carbon steel tends to maintain a sharp edge longer but can require more care in the way of blade cleaning or coating of the blade to prevent rust. Either way, if you go with one of these materials, you haven't made the wrong choice.

The handle can be composed of various materials from hard rubber to many other polymers.

The handle should be knobbed or grooved to fit your hand. A smooth handle makes the knife too slippery at best and too dangerous to use safely at worst. We already warned against a handle that is hollow. While it looks cool to pull out some candy from the handle of your survival knife like a PEZ dispenser, it doesn't look cool when your blade breaks off during actual use of the knife. Avoid hollow handles and be sure the handle has some sort of texture for gripping purposes and you should be all right.

The weight of a knife can vary greatly.

How you will carry the knife makes a difference when choosing the weight. Will it be sheathed on your hip? Will it be in your bag? If you are going to carry it separately in a pack, then weight doesn't matter as much to you. If you want it sheathed on your side then 3 to 6 ounces is probably a good place to fall between. This is highly subjective so I propose you go to a place that you can try knives of various weights to see what matches you best.

The design of the blade has a few implications.

A straight edge is simpler to sharpen. A serrated edge can cut things like rope better but will usually require a special sharpener. Some survival knives have a serrated edge on top of the blade and a straight edge on the bottom of the blade. This is a great design if you want both edges in one knife. Having both on the same edge can be tricky to sharpen. Another thing to consider is the width of the blade. In general the blade should be 3/16 to 5/16 inches thick. You don't want any kind of flex in the blade. Blades that thick can be used for chopping wood or prying things open. A bendable blade is not a desired feature in a survival knife.

Obviously there are many options and variations when choosing the best knife to do the job, but hopefully with these tips you will have a better concept of what to look for and will avoid some of the common pitfalls when choosing a survival knife to fit your needs.