Knives can be utilized as a weak melee weapon, though their best use is in a crafting table where you can carve bowls, make leather armor or process cereal crops, sheepskin and soaked hide. As of Build 77, Knives are also used to collect Straw from tall grass. Knives are available in either stone or metal material; metal knives work exactly like stone knives do, the only difference is durability.
Craft Leather Armor by placing a piece of Leather into the crafting grid with a knife, or by right clicking with a piece of Leather in hand and a knife in your hotbar. This will open up an interface similar to that of the knapping interface. The patterns you can make are the same as the patterns used for metal armor Plans.
Crafting Knifes
Stone Knife
Stone Knifes in order of increasing durability: Sedimentary, Metamorphic, Igneous Intrusive, Igneous Extrusive.
Knife blades can also be crafted by using ingots on an anvil with a hammer. This is the only option for higher tier metals that cannot be cast. The durability depends both on the metal used and the skill of the smith forging the tool.