Thank you for your recent inquiry with The Home Depot. This 3 inch Glacier Bay Brass Grid Drain in Brushed Nickel will not fit into a 1.75 inch sink drain. We do sell a 1-1/2 in. Bathroom Vanity Sink Grid Drain Without Overflow in Brushed Nickel (Internet #306612122 Model #STD-BN) that may work for your needs. We appreciate your business and look forward to serving you in the future.
Yes, this will fit a 3-inch hole opening in the sink.
I urge you to look at a different kind of drain. Read the reviews. I (and many other people) had problems with this drain. I don't quite understand why it wouldn;t drain, but it wouldn't. I am assuming that this is going on a vessel sink as you have to drill the counter? There are two schools of thought...you can drill a 1-5/8" hole and have the drain washer and nut snug up to the countertop. Or you can drill a larger hole like 2-1/2", have the drain nut snug up to the sink and not the countertop. I will reinterate that you should look at another type drain. I had to remove this one and put in a pop-up instead, which I am much happier with.
I believe that to be true.
Get another type of drain. It is common for this type of drain to not work properly, especially if your sink does not have an overflow.
It is classified as a 1 1/4 " drain.