(Criterion NDT: Auburn, WA) -- Doctors, hospitals, and individuals depend on the highest quality hypodermic needles to administer medicines and draw fluids. Unfortunately, 100-percent visual and/or water-leak test inspection of the needle tubing or finished product for microscopic cracks or defects is nearly impossible. A hypodermic needle manufacturer has integrated automated eddy-current testing solutions from Criterion NDT in its production lines to test 100 percent of its material for cracks and defects.

Situation

Medical-grade hypodermic needles are available in numerous diameters and wall thicknesses. A hypodermic needle manufacturer wanted to detect through-wall cracks down to 0.100 in. (2.5 mm) long × 0.004 in. (0.1 mm) wide in needles down to 0.011 in. (0.28 mm) in diameter.

The manufacturer’s process commences with forming and welding medical-grade stainless steel. The tubing is drawn through forming dies, annealed, and then straightened prior to cutting.

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