19 inch rack mounting strips

These are 2U and 4U mounting strips for mounting 19inch rack mounted equipment. They are screwed to the sides of a wooden 19 inch cabinet. Instead of having square mounting holes to take caged nuts, I designed these mounting strips with 5mm round holes which then need to be tapped with M6 thread. I found it best to clean the holes with a 5mm drill before tapping the threads. The holes for screwing the mounting strips to the cabinet are 4mm. These mounting strips are strong enough for quite heavy