Suitability

The intended usage of a tool is the basis for defining its features. The features of a tool determine its appropriate usage. Tools should perform reliably when used appropriately. A tool is sometimes applied to a task it was not intended for (e.g. a screwdriver applied as a chisel). In this instance, the performance of the tool may not be satisfactory due to an unrealistic expectation or failure of an implied capability. Recognizing unintended uses of a tool adds strength and character to it.

Not surprisingly, a small screwdriver is appropriate for turning small screws. This application assumes a set of criteria:

• the width and thickness of the blade should accomodate a target set of screws.
• the handle should provide a satisfactory human/tool interface within the constraints of comfort, torque capability and size.
• the proportions should be suitable for the target operating environment.