Implant Mechanix – Design & Innovation

Shown are 2 shots of a micro sized medical part in 17-4 PH stainless steel.  The part is micro drilled, wire EDM cut and the cut-off stub is hand finished.  The part is tiny: it is 0.050″ (1.25mm) long and 0.030″ (0.75mm) wide.  The wall thickness is 0.004″ (0.1mm) at the thick points and the part is accurate to within 0.0003″.  It was a challenge to cut this tiny part, mostly because of the difficulty in not losing or destroying it when it was cut off from its stem.

		The part still in the EDM worktank and attached by a tiny stem to the material blank.  The 0.015″ start hole for the next part is also visible.  The stem is 0.005″ wide

		The finished, hand dressed part.  Parts this small are hard to hang on to and stabilise for hand finishing.  This is microscope and tweezer work, and a minor mis-step with the tweezers means you’ll never find your part again!  On the right side of the shot you can see the ruby file and diamond file used to dress off the cutoff vestige from the wire EDM process.  The part is the tiny black rectangle just to the left of the penny. (Click the thumbnail to enlarge it)

Here is a prototype  implant component made from titanium alloy.  It is a laser welded assembly with turning, wire EDM, sinker EDM and laser welding all on a unit less than 5mm tall and about 5mm diameter. 

		The center screw can rotate inside the mating part but is captive.  A laser welded collar holds it in place

		This is an end-on view of one of the screwdrivers that forms part of the assembly.  It is wire EDM cut from hardened 420M stainless steel, and has a taper to allow it to jam into the screw socket.  It also has a center hole to permit another screwdriver to go through it.  It is about 0.080″ diameter at the tip.  The knurled screwdriver head is 304 stainless steel and was laser welded onto the tip