I present my 25mm long, 1/4" hex, insert driver bits.
This model contains 8 separate hex bits:
Two of the bits have Phillips-style drivers (PH1 and PH2),
Another two have Pozidriv-style drivers (PZ1 and PZ2),
While the last four are Flat Head/Slotted drivers (4.5x0.6, 5.5x0.8, 6.5x1.2, 8.0x1.6).
The bits can be identified using small sections of 6mm diameter heat-shrink sleeving in different colours (not included).
The bit's hex faces may need to be smoothed flat with sandpaper down to measure 6.35mm between faces, to ensure they will fit into all 1/4" hex slots and holders.
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.