Help drilling two holes in my cast iron tub.

I need to drill two small holes in my cast iron bathtub. All I know is that I need a hole saw to do it. Is there anything else I should know before I drill my hole? I don't want to screw up my tub.

Thanks

holes

A regular hole saw will not work. You need a carbide hole saw to cut through the porcelain and a metal cutting hole saw to cut the cast iron. To do it properly, you need the special set designed for doing this job. It has the necessary hole saws and is spring loaded to prevent applying too much pressure which could "craze" the enamel.