People who want to drill holes in their enamelware can run into problems due to the nature of the dishes. According to Ace Hardware's website, enamelware features a hard enamel exterior baked over a solid metal interior. The combination of materials gives homeowners the best of both worlds; the metal transfers heat evenly while the enamel allows for easy cleaning in a variety of colors. However, metal and ceramic require very different drilling tools and techniques. You'll need to use all of them when you drill through enamelware.
Place a strip of duct tape where you want to locate the hole.
Load a carbide-tipped masonry bit into a variable-speed drill. Lower the rpm on the drill to its slowest speed.
Drill through the duct tape and into the enamel while applying minimal force to the device. Listen for the sound of the drilling to change. Remove the drill and check the enamelware to make sure you've reached the metal underneath.
Remove the carbide-tipped bit and install a high-speed steel bit. Set the drill speed to normal.
Set the bit into the hole you've created through the enamel. Drill through the metal portion of the enamelware. Remove the drill once the sound changes again.
Replace the high-speed steel bit with the original carbide-tipped bit and lower the drill speed once more. Finish drilling through the final layer of enamel.