M5
Thread Diameter - M5 (5mm)
Pitch - 0.80mm
Socket Wrench Size - 4mm
Head Diameter - 8.5mm
Head Depth - 5mm
M6
Thread Diameter - M6 (6mm)
Pitch - 1.0mm
Socket Wrench Size - 5mm
Head Diameter - 10mm
Head Depth - 6mm
M8
Thread Diameter - M8 (8mm)
Pitch - 1.25mm
Socket Wrench Size - 6mm
Head Diameter - 13mm
Head Depth - 8mm
The length of the cap head screw/bolt is measured from the underside of the head to the end of the thread