Standard American wrench sizes, from the largest to smallest and measured in inches, are 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. Wrenches are available in a set or individually.
A small set has six to 10 wrenches, ranging from 5/16 to 1 inch in size. Standard wrenches are available in packs of 1/16 inch increments up to 1 1/2 inches. The tool’s length varies proportionally to size, ranging from 4 inches to 2 feet; a longer tool maximizes the force required to tighten a larger nut and vice versa. Length also helps avoid shearing off bolts in case of excess pressure application.
Two wrenches of a similar kind and size can have widely varied price tags, as the manufacturing process and materials used to create each of them is different. Vanadium or chrome alloy wrenches tend to be of the highest quality and hence the most expensive, while sheet metal and molybdenum wrenches are cheaper. Sheet metal stamped wrenches tend to be bulky and are best for environments where strength is required. They are also the best choice for infrequent light-duty work. However, for regular use such as automobile applications, the pricey tools are a better investment.