We are offering deep hole measurement gauges. Deep bore measurement:sangha produce deep bore gauge for deep measurements.by deep bore gauge you can measure 100mm deep bore measurement with accurately. see full detail in pdf file. to design the anvil for deep bore measurement,the following information is required: how to understand: ed:smallest dia through which the given head has to pass l:length at which measurement is req.(add extention if required) dc:depth of clearance for cover plate(if there is no bottom or head clearance,extra special anvil design can be provided).