"Anyone who's been in a wilderness survival situation knows that a survival knife is one of the most valuable things to have. While there are means to fashion a knife out of materials from the wild, it's still incomparable to the strength of a steel blade. Military surplus stores often have a wide selection for these knives and other survival gear, leaving one with the question of how to choose the best one. The most important part in the selection process is knowing what the knife is to be used for. While it will ultimately come down to personal preference, there are certain characteristics to look out for in choosing a survival knife. Those in need of a specialty knife need to look at the tang, the blade edge, the type of metal the blade is made of, and the knife handle before settling on a knife to buy."

http://www.specialforces.com/blog/industry-news/tips-on-selecting-the-perfect-survival-knife-from-military-surplus-catalogs.html