M3 / M4 Tap Handle

Here is a tool to use for a M3 and M4 tap with a square drive on each side of the main shaft to assist in tapping the flipper components. I based the design on M3 & M4 Suttons Taps with the square drive measurement across the flats on a:M3 = 3.15mmM4 = 4mmI am not sure if this is a industry standard sizing. So to allow for shapeways variance slight variance of 0.1mm I have added an addition 0.14mm = 0.24mm in total each way. I will purchase one to check.