Published at Wednesday, August 01st 2018, 01:52:57 AM by Lorie Shelton. Knives. The blade on survival knives. As a rule of thumb you should avoid survival knives with a double cutting edged blade. This weakens the tip and also increases the risk of getting cut while performing tasks with survival knives. Some of these tasks may include cutting, slicing, prying, chopping or digging. Fixed blade survival knives should have a full length tang. This means the blade on survival knives should be a single piece of steel that runs all the way through the handle. The blade should be good quality steel that is strong and will also keep a sharp edge.