Stated sizes refer to thread diameters, i.e. M6 = 6mm thread diameter.
M4x0.7mm pitch; spanner size 7mm, overall height 8mm.
M5x0.8mm pitch; spanner size 8mm, overall height 10mm.
M6x1.0mm pitch; spanner size 10mm, overall height 12mm.
M8x1.25mm pitch; spanner size 13mm, overall height 15mm.
M10x1.5mm pitch; spanner size 17mm, overall height 18mm.