5/8, 19/32, 9/16, 1/2, 7/16, 3/8, 11/32, 5/16, 9/32, 1/4, 7/32, 3/16, 5/32, and 1/8 are the standard American wrench sizes, measured in inches from biggest to smallest. Wrenches can be purchased as a set or separately.
A small set has six to ten wrenches in sizes ranging from 5/16 to 1 inch. Standard wrenches come in 1/16 inch increments up to 1 1/2 inch in length. The length of the tool varies with the size of the nut, ranging from 4 inches to 2 feet; a longer tool optimises the force necessary to tighten a larger nut, and vice versa. In the event of excessive pressure, length also aids in preventing bolt shearing.
Because the manufacturing process and materials used to make each wrench are distinct, two wrenches of the same type and size can have vastly different price tags. Wrenches made of vanadium or chrome alloys are the greatest quality and thus the most expensive, whilst sheet metal and molybdenum wrenches are less expensive.
Sheet metal stamping wrenches are large and are best used in areas that require strength. They’re also the ideal option for occasional light-duty tasks. The more expensive instruments, however, are a better investment for regular use, such as in vehicle applications.