Flange for Cyclone Dust Sepatator

This flange is to mount a Suning SN50T3 Cyclone (sold without flange) to a cheap plastic bucket lid without gaskets or sealant. The cyclone separator is placed between a vacuum cleaner and the CNC router or miter saw and to catch the sawdust so I'm not constantly changing filters. The flange is 5 mm thick and 150 mm square and is to be mounted on the lid with 1/4 inch bolts. The M4 self-tapping screws are installed from underneath the flange and into the cyclone before it is bolted to the lid.