I inherited a 30mm thick granite worktop and need to cut a 100mm diameter hole in it. The hole doesn't have to be pretty, as it will be covered completely by a Belfast-like sink. I'm probably going to have to buy/rent a 100mm diameter diamond hole cutter, but was wondering if: I could get away with drilling a ring of smaller holes and knocking out the centre I could make the hole once the worktop is fully installed what the likelihood is of cocking it up, e.g. cracking the slab I've watched a few YouTube videos on doing this and they all look reasonably straight forward, but I'm sure you kitchen fitting pros out there would have some great tips/suggestions/warnings/etc.
Search Amazon for diamond hole saws, this type.. work great in granite/porcelain. Never done a 100, but did a couple of 76mm holes in 20mm granite slabs a few months ago and they only took a few minutes each. Just make sure to keep them well watered.
Thanks. I've seen them using angle grinders and other using drills. Do the drill ones turn fast enough?
A decent combi drill works just fine, the bits have a thin wall ( 1.5mm or so) and tackle granite with ease. I have several - more expensive - diamond hole saws that I haven't used for years because these 'cheap as chips' ones do the job much faster. The 76mm saw I used on the granite slabs had previously been used to drill 7 other holes in porcelain tiles IIRC and is still going strong.