Wrench

A wrench, called a spanner outside North America, is a tool used to provide grip and mechanical advantage in applying torque to turn objects, usually rotary fasteners such as nuts and bolts, or to keep them from turning. Wrenches and similar turning tools have been noted by historians as far back as the fifteenth century, and adjustable coach wrenches for wagon wheels were manufactured in England and exported to North America in the late eighteenth and early nineteenth centuries. The mid nineteenth century saw patented wrenches that used a screw to adjust the width of the jaw, including the patented monkey wrench. Higher quality wrenches are typically made from chromium vanadium alloy tool steel, often drop forged and chrome plated to resist corrosion and simplify cleaning. British, Irish, Australian and New Zealand English use spanner as the standard term, while American English reserves spanner for a specialized wrench with pins or tabs around its circumference rather than jaws.