Northfield Precision Instrument Corp. reported that when a customer requiring a highly specialized diaphragm chuck was not finding success with other chuck manufacturers, they turned to Northfield Precision Instrument. The chuck needed to be submersible for use in a wire EDM. To achieve this, the engineers at Northfield designed a specialized chuck with all non-stainless steel wetted parts.

For ultimate protection in a corrosive environment the chuck was fully coated with a thin, dense layer of hard chrome. In addition, the top tooling had to be custom designed to hold the customer's specialized part (not shown) to within 0.0002" TIR accuracy and repeatability.