At the threaded bit, an M4 would be 4mm across. … It’s a bit more accurate than that, everything from the diameter of the bolt without the thread to the shape of the thread is defined to a tolerance.

What diameter is an M4 bolt?

ThreadMajor DiameterPitch DiameterM44.03.545M4.54.54.013M55.04.480M66.05.350

What is M4 measurement?

Broad money e.g. M4 money supply is defined as a measure of notes and coins in circulation (M0) + bank accounts. It is a broader definition because it includes bank accounts and not just notes and coins in circulation.