I present my sprued model of four 25mm long 1/4" hex insert driver bits.
Two of the bits have a No.2 Phillips-style driver profile (PH2) while the other two have a No.2 Pozidriv-style driver profile (PZ2).
The bits can be identified using small sections of 6mm diameter heat-shrink sleeving in different colours (not included).

Note:- The model has been modified since the initial printed bits shown in the pictures were received and tested; there is no longer a ring half-way up the hex section of the bit as it caused a problem with certain types of bit holder.

The individual bits will need to be separated using a Dremel tool (or similar) with a mini grinding disk attachment and the bits hex faces will need to be smoothed flat with sandpaper down to measure 6.35mm between faces.

These bits will not be nearly as strong as commercially available ones and exist purely as a test of printed stainless steel's detail resolution and strength limitations.
Although having said that they should be strong enough for use with hand tools, just not with power drivers and especially not with impact drivers.

There are some more photos of this object and other examples of my work, both 3D printed and otherwise, on my 'Tofty' facebook page.