Standard Sink Drain Size
While a bathroom sink s design and overall size may vary from one model to the next the drain holes are fairly standard 1 25 inches being a general standard with widths of 1 5 inches and 1 625.
Standard sink drain size. This is the measurement across the center of the drain from one side to another. The drain strainer the bowl shaped piece inside the drain mouth matches this dimension. According to signature hardware a standard kitchen drain is 3 1 2 inches in diameter. Even if you get a new faucet for the bathroom sink you need to buy a drain of these sizes.
However most of the bathroom sinks use 1 inch drain pipe.
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