Wrench
A wrench or spanner is a tool used to turn bolts or other hard-to-turn items. There are many types of wrench, including the:
- open-ended spanner: a one-piece spanner that grips two opposite faces of the nut
- adjustable spanner/wrench: an open-ended spanner/wrench with adjustable (usually smooth) jaws
- monkey wrench: adjustable wrench with serrated jaws (depicted above right)
- ring spanner: a one-piece spanner that encloses the nut on all sides
- combination spanner: a double-ended tool with an open-ended spanner at one end and a ring spanner at the other
- spoke wrench
- Allen wrench
- hand wrench
- pipe wrench
- strap or chain wrench: a self-tightening strap or chain attached to a handle, used to grip and turn smooth cylindrical objects
- oil-filter wrench: a type of chain wrench for removing cylindrical oil filters
- socket spanner/wrench: a hollow cylinder that fits over one end of a nut
- box spanner: a tube with a socket formed at one end, that can reach a nut at the bottom of a hole or in a restricted space
