Bathroom vanity sink faucets require specific drilling holes to mount the faucet on the sink. These holes are standardised for ease of installation, and different faucets install on a variety of pre-drilled sink tops. However, if you are drilling your own sink faucet holes, there are several things to consider. Not all sink faucets are drilled the same way, and some allow for different drilling hole distances and sizes.
Different sink faucets have different sized mounting hole diameters. This is the diameter of the handle bases and spout. Each mounts right into the sink counter top, so cutting a hole of this size is necessary when installing any type of sink faucet. Even if the faucet has a single hole with a base, or two handles with a connected base, the mounting holes must be drilled correctly. Most hole sizes are either 1 1/4 inches or 1 1/2 inches, but there are other hole sizes in that range. Your faucet manual will tell you which hole size your faucet has.
A single-hole faucet has only one mounting hole and typically it has just one handle. This means the spout mounts right into the counter top. There is just one base shaft on which the spout and handle are attached. To drill a hole for this type of faucet, simply note the hole size, choose the corresponding hole saw size, mark the location of the spout base and drill through the cabinet. Install the faucet by inserting it into the hole.
Center Set Faucets
A centre set faucet has two handles set at the same distance from the spout. These handles are 4 inches on centre (meaning from the centre of the spout, not the edge) from the spout. The handles each have a shaft that extends through the counter top. The drilling hole size is usually the same for the handles, but may differ on some models. The spout hole is typically drilled first, then the handle holes drilled by measuring and marking off 4 inches from the spout.
A widespread faucet has two handles set at a variety of distances from the spout. The distances range from 6 to 15 inches, depending on your model. Typically, the faucets have two independent handles with their own mounting shaft. A hole size matched to the diameter of the mounting shaft (typically between 1 1/4 and 1 1/5 inches) is used to mount these faucet handles on the counter top. The spout is also installed using a mounting hole within that size range. Since the handles are independent, they are mounted at any distance the user sees fit, but the distance from the spout normally is the same on each.