A thickness of 0.5mm is more than adequate for most situations, as high frequency screening operates on reflection principles. More important considerations are choice of a suitable non-ferrous base material, adequate earth pinning and quality of assembly with regard to soldering to ground.
Using a material that is too thin in the hope of making savings can cause problems. The flat 'blank' or screening can must be self-rigid in manufacture to minimise problems involved with handling a weak product. One of the fundamental advantages of PCM RFI cans may also be compromised - the etch bend line. If the material is too thin, a typical bend line etched 50% to 60% into the blank would induce micro-cracking and cause the can to break along the line when folded. It is unwise to use blanks with a thickness of less than 0.25mm (0.010") when using fold lines. If this cannot be avoided, brass will give greater mechanical strength.
If cans or fences are to be board mounted then board pins may be incorporated on the seating edge of the device. For pick and place assembly, no pins may be required, or just 2 or 3 for location purposes. If wave solder or hand soldering techniques are to be used, adequate board mounting pins should be allowed for to ensure sufficient screening at the seating edge level. For good connection to ground, the pins must connect to a suitable ground plane or some other earth, such as the enclosure or device.
Caution: It is impractical to place board mounting/locating pins at the corners of a fence or can.