No.4 = screw dia. 2.9mm, head dia. 7m, head height 1.9mm.
No.6 = screw dia. 3.5mm, head dia. 8m, head height 2.1mm.
No.8 = screw dia. 4.2mm, head dia. 9.8mm, head height 2.3mm.
No.10 = screw dia. 4.8mm, head dia. 11.2mm, head height 3mm.
No.12 = screw dia. 5.5mm, head dia. 12.8mm, head height 3mm.
All dimensions are subject to manufacturing tolerances.