Starret, Bosch, but I think you'll struggle whatever you use. I think some of the guys who visit here recommend chain drilling. Either way cast is a b***h.
been watching this post myself for some idea's, i have never been able to cut a hole into a cast pipe, i tried once and failed! so now i just replace in plastic
Use a starret hole saw and use a drill with a low spin speed. Get some cutting oil and a squirt can and get someone to keep the drill cool by giving it a squirt now and again, take your time and you'll get thru it.
I found absolutely no problem drilling a cast flue pipe using a lennox saw and after grinding away the vitreous enamel. I used a DeWalt on it's lowest speed and just kept the speed down. No lubricant either. No problem.
I see what you mean about low speed cutting, keep the heat down etc.
Regarding low speed cutting, I bet it wouldn't take much too crack a bit of the cast off if the drill were to jam on a higher speed..
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local