Box end wrench (top) and open end wrech (bottom). Photo: Getty Images
According to the Merrian-Webster's
dictionary, the word wrench
derives from the Old English wrencan
which means "to twist." Some things don't change with time, so like the etymology implies, the modern day tool is used for turning an object, commonly a hex-headed bolt
or a nut.
There's a large variety of wrenches out there
, each with its own specific function. They all fall into two broad categories: adjustable and fixed. From there, the most common types of fixed wrenches are the open-end wrench, the box-end wrench, and the combination wrench.
Open End Wrench
- This is the classic wrench that consists of a simple handle with a 'c' shape at the end of it. Its function is basic; set the open end around a nut or bolt so that the edges of the wrench are tight to the sides, and turn. Open end wrenches come in both metric and SAE (inches) increments.
Box End Wrench
- These are similar to their open ended cousins except for the fact that the end is a closed 'o' instead of an open 'c.' These are nice because they apply pressure to all sides of the nut evenly, as opposed to the two sides that an open end wrench uses. The limitation with them is that you need the clearance to get the wrench around the nut.
- Combo wrenches are nothing more than a wrench having an open end on one side and a box end on the other other. A basic set of combination wrenches usually goes for $20-$30, so if you want both SAE and metric, you can expect to be in the $40-$60 range.