@web_goddess@aus.social Those fire pits look like they are a couple of millimeters thick, so you'll likely need a stronger drill bit made of cobalt. I'd go with a 4-6mm bit, to effectively drain but minimise size of hole. This looks reasonable: https://www.bunnings.com.au/full-boar-5-5mm-m35-cobalt-drill-bit_p0331109 However you make the hole, make sure you're wearing long sleeves and eye protection — metal splinters are painful and harmful.