Note that some local hardware stores sell this edge trim by the foot. Last, covering the cut edge with edge trim gives it a professional appearance and offers more protection for your knuckles from the sharp edge of the sheet metal. You will need a grill too and I recommend getting a quality diamond lapidary wheel to finish the edges to save your knuckles from the jagged edge caused by the saw. Then blast out (or even carefully hose out) the interior to ensure no metal filings fall onto or into any of the electronics, or are left behind. One word of caution - take everything out of the case before drilling your 6 holes (one pilot hole, one big hole for the air vent plus 4 mounting screw holes) and before edge grinding/finishing.

Blowhole fans are very effective at increasing cooling efficiency but if your case sits on or near the floor, the top mounted fan may produce some undesirable fan noise.

Click to expand.We used to do this often back in the day - making 'blowhole' (top) fan locations.

Dell xps fan control