Hexagonal and other polygonal headed fasteners, commonly known as nuts and bolts, are used across many industries for various applications. When working with these fasteners, wrenches and/or sockets are required for their installation and removal. With a wide array of sizes and a lack of indication on nuts and bolts specifying their exact size, the most common practice in determining an appropriate tool size is to guess using visual estimation. This leads to a myriad of problems.
Guessing an appropriate wrench size is inefficient and difficult to do correctly, even for the most experienced technicians. Most people who have worked with nuts and bolts have experienced the frustration of making an incorrect wrench selection. Taking automotive repair as an example, frustration can build when an incorrect wrench is repeatedly selected, requiring an individual to exit and re-enter an uncomfortable or awkward position commonly associated with repairs, such as under an automobile.
There are two standard units of measurements used in fastener fabrication, Standard (Inch) and Metric (mm). With a growing global economy and increased prevalence of outsourcing, it is becoming more common to see metric fasteners in the United States. Since the global economy has made trade of industrial goods more prevalent, technicians and the general public must now be more comfortable with metric fasteners in addition to the historically popular standard inch dimensions. The dual measurement system has caused more confusion than ever due to the increased number of nut and bolt sizes. With the increased prevalence of metric fasteners, individuals may unwittingly select a standard inch wrench when a metric fastener is required. This can lead to stripping the head of the nut or bolt, injury from wrench slipping, frustration and major inefficiency in completing a task.
Previous attempts at solving these problems have included designs such as that shown in U.S. Pat. No. 7,373,735. However, many of these are more conceptual that actually functional in the industries in which they were intended for. They are more expensive, and not as simplistic and intuitive as they could be. Additionally, they do not maintain an accurate size fastener size after being moved away from a fastener. Further, they measure from one flat side of a fastener to an opposing flat side, which can make measuring more difficult and further, are not biased against the fastener measurement location which can lead to problems with accuracy.
Thus, needs exist for improved techniques by which to accurately gauge the size of fasteners such as nuts and bolts.