Had to dig for this pic. This was after a couple of laps and my brake disc failed. The drilled holes had cracked and the cracks kept weeping towards the hub, luckily it didn’t go all the way round. Both sides were like this but this pic was the worse of the 2. Since then I never touched drilled discs. Goes to show it pays to get good brakes, discs and pads. Not worth the risk IMO.