Cross recessed (+) raised countersunk head screw(Coarse Stainless steel Unplated 3 X 6 Pitch 0.5

The top surface of the countersunk head has a rounded shape. A flat countersunk head can be installed flush with the mating surface, but when something is slid across the surface, it may catch on the slot groove or the recess of the cross hole. While an oval countersunk head cannot be installed flush, it prevents snagging on the slot or cross recess. Since the slot groove or cross recess can be made deeper than the countersunk bearing surface, it allows for a more secure engagement with the screwdriver.
Although it protrudes more than a flat countersunk head, it still has a lower profile compared to a pan head. It is used when a prominent protrusion is undesirable, yet a flush finish is also not preferred. Since it resembles a countersunk head with a decorative touch, it is perfectly acceptable to choose it based on design or aesthetics.
Machine Screw Head Dimensions Reference Oval Countersunk Head Screw Encyclopedia

• Cross recessed (+) raised countersunk head screw Coarse pitch
• Nominal diameter (d) M3
• Length (ℓ) 6.0
• Pitch 0.5
• Cross recess number 2
• Head diameter (dk) Nominal 6.0 Tolerance 0,-0.5
• Countersunk head height (k) Nominal 1.75 Tolerance 0,-0.3
• Chamfer (C) Approx. 0.25
• Dome height (f) Approx. 0.7
• Head height (k+f) Nominal 2.45 Tolerance 0,-0.5