Measuring Tapers

One of the most common production practices of determining a good taper from bad is a trial and error method called "blueing." Blueing is a process which uses a precision "master taper" or part having its tapered feature manufactured to more stringent tolerances on size and angle than the actual workpiece to be measured. In use, the master taper is lightly and evenly coated with a film of dycom or indelible ink, and then inserted into the mating tapered workpiece. A slight twist of the joined master and workpiece is given, then the master removed for visual inspection.

Air gaging has become one of the most economical and reliable solutions for fast accurate, non-subjective measurement with variable data as a result. The relatively low cost of such tooling, combined with self-cleaning properties of air tooling and the serial output from today's digital air-to-electronic columns, offer distinct advantages over more flexible universal type gages or "jury rigs." They are also fast, accurate, repeatable, and suitable for shop floor production use.