Pipe wrench Pipe wrench A pipe wrench is any of several types of wrench that are designed to turn threaded pipe and pipe fittings for assembly (tightening) or disassembly (loosening). Especially in North America, the Stillson wrench or Stillson-pattern wrench is the usual form of pipe wrench. (The name comes from the original patent holder, who licensed the pattern to multiple manufacturers; the patent expired decades ago.) Another type of wrench often used on pipes, the plumber wrench, is also often called a pipe wrench, depending on locale. The Stillson type is an adjustable wrench/spanner with hardened serrated teeth on its jaws;
Tool stone materials, such as basalt, granite, and sandstone, may also be used as tool stones, but for a very different purpose: they are ideal for ground stone artifacts. Whereas cryptocrystalline materials are most useful for killing and processing animals, large-grained materials are usually used for processing plant matter. Their rough faces often make excellent surfaces for grinding plant seeds. With much effort, some large-grained stones may be ground down into awls, adzes, and axes. Tool stone In archaeology, a tool stone is a type of stone that is used to manufacture stone tools, or stones used as the raw material for