Automotive Box Wrenches

For the mechanic, automotive box end wrenches are a necessity. These tools come in a variety of sizes and are available as complete sets or individual pieces. Getting a well-made set of box end wrenches is an investment that can last as these tools can be passed on to future generations of mechanics.

What is a box end wrench?

The box end wrench, also known as a box wrench or ring spanner, is a lever tool with a cylindrical head that has been bored to fit over a hexagonal nut. The inscribed hexagon of the wrench may have additional points, providing more contact surfaces and versatility in getting the box end wrench onto the nut. In some cases, a box end wrench is double-ended and may have an offset on either end that features another closed end of a different size or an opened end of the same size. The handle of the wrench serves as a lever to rotate the nut, thus giving the user more torqueing power. The box end of the wrench is completely enclosed to prevent slipping off or rounding the corners of the nut. These tools are commonly manufactured from stainless steel or chrome vanadium alloys, but special use box end wrenches are available in other materials.

What are box end wrenches used for?

Box end wrenches are commonly used in hard-to-reach areas where visibility is reduced or where an adjustable wrench would not be practical. The ability to securely hold the nut prevents loss and makes it easier for mechanics to use the wrench without visual cues. By rotating the shaft of the tool around the nut, it is possible to loosen or tighten the fastener. In addition, the wrench can be used to hold a nut in place while using another wrench or a socket wrench to turn the bolt that connects to the nut. These wrenches are used for a variety of metal fabrication and mechanical projects, including automotive applications.

What sizes of box end wrenches are available?

Box wrenches are commonly available in metric or standard sizes. Metric sizes are displayed as a number followed by the abbreviation "mm" for millimeter and look something like "XX mm." Standard sizes are based on inches and are usually displayed as a number or fraction of a number that may be followed by the " symbol. These designations usually look like "XX" or "X/X." The size designation comes from the across flats distance of the inside surfaces of the wrench. For example, a 3/4-inch wrench will fit a 3/4-inch nut but will not fit a 5/8-inch or a 1/2-inch nut properly.

Special use box end wrenches or those made for a single purpose, such as fire hydrant box wrenches, may also be available in custom sizes to fit specific needs. Except in the case of specific use tools, these tools sizes are usually displayed in the same manner as their counterparts. Specific use tools may be unlabeled or labeled with their appropriate use.