Keys are a common way of fastening items such as sprockets, pulleys and gearboxes on to cylindrical shafts. A key is defined by being a removable element that is capable of transferring torque between a shaft and a hub. In general, keys are either square or rectangular and are usually parallel/flat, although gib head keys for example utilise a taper.
Material mechanical properties form the basis of any component design, ensuring that the component can operate under the required working loads without changing its configuration or microscopic structure. These properties are often found experimentally by using material test samples. It is often the case when performing these experiments that two samples from the same material, tested on the same machine, give different values. To ensure the safety of any component manufactured from a material, the property data is often given as the minimum range or value in their corresponding data table.