Hunting down the right bushcraft knife can be a time-consuming process, to be sure. You can spend hours learning about different knife designs, steel types, blade geometries, and so on when shopping for a survival knife — but to save you some time, here's a quick and dirty survival knife buying guide to get you started:
Blade size
People have strong opinions about blade size, but as a general guideline, the sweet spot for a survival/bushcrafting knife is 4 to 5 inches ( 6 to 7 inches is also acceptable for a general-purpose blade). Some survivalists and outdoorsmen subscribe to the "big knife" school of thought, as you can get a lot more done with a large blade, reducing redundancy among the other tools you're carrying.
Whatever size of survival knife you choose to carry into the wild, it's best to go with a blade that's at least 4 inches long. Any shorter and it'll be too small for many tasks. Also, consider that it will always be easier to perform small tasks with a bigger blade than it is to tackle big jobs with one that’s too small.
Blade geometry
"Blade geometry" refers to the general shape of a knife's blade. As different knives are built for different tasks, there's no "one size fits all" blade shape even for rather specific niches like bushcrafting. Drop points and clip points are the styles you'll see the most among modern knives made for survival knives owing to their time-tested versatility.
Drop point blades are the most favored among survivalists, as the tip is more durable than that of a clip point (which comes to a sharper tip, thus making it more likely to break) and stands up well to rough use, but the sharp end of a clip point has some advantages of its own. Bushcrafting knives should also feature a robust grind that will leave the blade less susceptible to chipping or cracking along the edge.
Materials
You can spend hours and hours learning about different blade steels before even approaching other design considerations. To keep it very brief, steels are divided into two main camps: stainless, which is more resistant to corrosion but typically softer, and carbon, which is less rust-resistant but holds an edge better.
The ideal hardness for a survival blade on the Rockwell scale is 58-60 HRC. Too soft and the knife will be tricky to sharpen properly and won't hold an edge well; too hard and the blade will be brittle and prone to breakage.
Stainless had a bad reputation years ago (mostly due to poor steels that you typically find on cheaply made knives), but some companies like Buck and Morakniv make very good stainless blades today. The most common carbon steel you'll see is 1095 owing to its ease of manufacturing, low cost, good edge retention, and durability when properly heat-treated. Other carbon tool steels, like A2, D2, and CPM-S30V, may have better properties (superior edge retention, corrosion resistance, etc.) than 1095, but are pricier.
Grip material is also important. Many users today, myself included, favor Micarta (made from compressed layers of linen, cotton, or paper), as its rough surface texture provides excellent purchase on the handle even when your hands are slick with sweat, water, grease, or blood. Leather and polymer handles are also rather common, but generally inferior to Micarta in both grip and durability, although there are ways to improve these shortcomings.
Origin
Knives are manufactured all over the world, but for a knife that you may end up having to rely on to survive, we strongly recommend sticking with qualified and well-known blade-makers in the US, Europe, and Japan. You typically don't have to pay out the nose for one of these blades, either. Stay away from the ocean of cheaply made junk from no-name brands (often made from low-quality stainless steels with poor heat treatments to match) that litters the internet.
That's not to say that all knives that come from China are poor quality, but as a general rule, the best blade-smiths in the world are located in America, Europe, and Japan — places with long traditions of quality smithing. Although our own picks are made in America and Europe, there are also some very solid blades coming out of countries like El Salvador (Condor), Brazil (Tramontina), and Taiwan (many of Cold Steel's offerings).