For example, if you look at a DIN 933 table for metric hexagon screws (https://www.schrauben-lexikon.de/norm/DIN_933.asp), you get for a M12 screw a wrench size of 19.0mm and a head height of 7.5mm.
This means, at a scale of 1:10 for an M1.2mm hexagon screw a wrench size: of 1.9mm and a head height of 7.5mm.
Various suppliers have model screws with high and "flat" heads.
For example, an M1.2mm screw has a head height of 1.2mm (high head) (https://ghw-modellbau.de/product_info.php?products_id=708&language=en) or 1.0mm (flat head) (https://ghw-modellbau.de/product_info.php?products_id=674)!
It always bothers me when I look at beautiful models that somehow look "strange" because of such screws.
In addition, some screw heads often have a pimple on the top.
So I drilled fifty 1.0mm holes in a small 1.5mm thick brass plate and cut 1.2mm threads. A bit tedious, as these taps have to be used with feeling, so two carefully forward - one back ...
In the following picture you can see a hole without a screw, because the thread cutter had left a piece of its tip.
Sechskantkopf_kuerzen_01 (fspg2)
(https://www.finescalerr.com/smf/proxy.php?request=http%3A%2F%2Fwww.buntbahn.de%2Ffotos%2Fdata%2F9341%2F2903Sechskantkopf_kuerzen_01.jpg&hash=fd2598f28f09b9150b30b97bab25ddc761fcba8c)
Two small boards were pasted with two different types of sandpaper - 180 grit on the left and 240 grit on the right.
First, two 0.8mm brass sheet strips were attached to the somewhat coarser sandpaper with superglue. Now the first rough polish was made.
Sechskantkopf_kuerzen_02 (fspg2)
(https://www.finescalerr.com/smf/proxy.php?request=http%3A%2F%2Fwww.buntbahn.de%2Ffotos%2Fdata%2F9341%2F2903Sechskantkopf_kuerzen_02.jpg&hash=89d306becb22f4e9462fc7497dae2151ac5b8ab0)
The same game took place on the somewhat finer sandpaper, here the two metal strips have a height of 0.7mm.
Sechskantkopf_kuerzen_03
(fspg2)
(https://www.finescalerr.com/smf/proxy.php?request=http%3A%2F%2Fwww.buntbahn.de%2Ffotos%2Fdata%2F9341%2F2903Sechskantkopf_kuerzen_03.JPG&hash=cc7bdcd6012f80ef1210a2a830a467b36ab6ac9a)
In order to break the ground edges of the screw heads, the plate was sandblasted with glass beads.
The back with the threads was protected by adhesive tape.
Sechskantkopf_kuerzen_04 (fspg2)
(https://www.finescalerr.com/smf/proxy.php?request=http%3A%2F%2Fwww.buntbahn.de%2Ffotos%2Fdata%2F9341%2F2903Sechskantkopf_kuerzen_04.jpg&hash=c264a0d23f0b3f547036f20691335b63b294f6b2)
Here again a comparison of the two head heights - both M1.2mm and wrench size of 2.0mm - head height left = 0.7mm and right 1.0mm + pimple.
A variant with M0.6mm hexagon screws and 1.0mm wrench size:
Demag_ML15_Montage_26 (fspg2)
(https://www.finescalerr.com/smf/proxy.php?request=http%3A%2F%2Fwww.buntbahn.de%2Ffotos%2Fdata%2F9409%2F2903Demag_ML15_Montage_26.jpg&hash=fef7e16db0438d32dc040498d3ce4ebc23cb95a1)
Here these screws (https://knupfer.info/shop/index.php/deutsch/modellschrauben-messing/messing-niedriger-kopf/301-06-06.html) were polished from 0.6mm to 0.4mm head height ground.
Demag_ML15_Montage_27 (fspg2)
(https://www.finescalerr.com/smf/proxy.php?request=http%3A%2F%2Fwww.buntbahn.de%2Ffotos%2Fdata%2F9409%2F2903Demag_ML15_Montage_27.jpg&hash=f04ea348912c50ffc9d00b1146ac84320e32b4e0)
Most impressive. -- Russ
Love that!
Such dedication, with excellent results!