M3 ~ i/d 3.2mm; o/d 9mm; 1mm thick.
M4 ~ i/d 4.3mm; o/d 12mm; 1.6mm thick.
M5 ~ i/d 5.3mm; o/d 15mm; 2mm thick.
M6 ~ i/d 6.4mm; o/d 17mm; 3mm thick.
M8 ~ i/d 8.4mm; o/d 21mm; 4mm thick.
M10 ~ i/d 10.5mm; o/d 25mm; 4mm thick.
M12 ~ i/d 13mm; o/d 30mm; 6mm thick.
M16 ~ i/d 17mm; o/d 40mm; 6mm thick.
M18 ~ i/d 19mm; o/d 44mm; 8mm thick.
M20 ~ i/d 21mm; o/d 44mm; 8mm thick.