Mega-bump !
So, I had stripped a few screws on K-mount lenses way before. Now I'm more cautious on applied forces, for avoiding the cam-out of the screwdriver. Plus, having Japanese-made cross point screwdrivers also helps.
Nevertheless, I have several lenses, which have been badly tinkered by previous owners. Some screws here or there need replacement, and I cannot find exact replacement parts for these K-mount miniature screws.
Here is what I measured with an old caliper :
- Apparently 2mm thread diameter, so a metric M2 thread, most probably a standard pitch.
- 3mm total length.
- Only about ~0.6mm head thickness, flat-type.
- 3 mm head diameter.
In my country, I have found only one online serious supplier for general public, that provides many micro-screws, with the appropriate data. But none of them are a good match for K-mount screws.
Their nearest equivalent that I found are described like this :
- DIN 7985 norm, mmmh OK,
- M3 , M2.5 , M2, or M1.6 or even thinner. M2 seems about right.
- 1.6 mm head thickness, which seems quite too thick,
- 4 mm head diameter, flat on the inner side, slightly bulbous on the tip side.
- Available with 3, or 4, or more total length.
So it would be maybe possible to take a 4mm length screw like this, sand the head to make it thinner, sand again the head but tangentially, in order to reduce its diameter down to 3mm or so.
And hope there is still enough material left to engage a PH0 / PH00 screwdriver properly.
I have some modelling tools to do the trimming. But it would be a lot of hassle, for each screw, and many to modify.
So if anyone has a better source for K-mount replacement screws, and confirm my measurements, it would be very nice indeed.