What size hole do I need to drill for a door knob? A standard door knob hole is 2 1/8 inches in diameter. This won’t have the best fit on older doors because their holes are usually smaller. If you’re looking to change or replace older door knobs, you need to re-drill the door to fit the current standard size.
How do you make a door latch hole?
How do you drill a hole in a metal door knob? Using a center punch, make a dimple in the metal in the middle of the latch and doorknob. You’ll see the indicated holes right in the template. This will mark where you need to drill. Pull off the template and connect the 2 1/8-inch bimetal hole saw to a 1/2-inch drill fitted with a drill bit for a steel door.
Which drill bit is for metal? Cobalt drill bits are used for drilling hard metal and steel. They dissipate heat quickly and are highly resistant to abrasions, making them better for drilling into hard metals than black oxide- or titanium-coated drill bits.