I need to make a 13mm hole. The largest drill bit I have is 8mm. My drill handles up to 10mm. I don't want to buy a new drill just for this one hole. Is there anything that would fit a 10mm drill that would make a 13mm hole?
If you are drilling into wood, no problem. You need a 13mm flat head bit. This will fit a standard chuck. If you are drilling into masonry, you might get away with a 13mm masonry bit, but check the shank diameter of the bit. A masonry bit has 'sticky out' parts at the business end. If drilling into metal, you will need a 13mm bit and thus a drill with a bigger chuck, unless you are able to change the chuck on your drill.
Obonio - you could buy a reduced shank 13mm drill bit. The shank of which, would be roughly 8mm in diameter, which would easily fit into a 10mm capacity chuck. Good luck.