Use one common board and allowance basisCountersink remaining thickness2.00 − 1.40 − 0.20 = 0.40 mmCounterbore remaining thickness2.00 − 1.10 − 0.20 = 0.70 mmHardware decisionCone and flat seat are not interchangeable³Ô¹Ïtv · Original engineering schematic · Illustrative, not to scale