A bathroom sink has several main parts:

1. Basin: The bowl-shaped part that holds water. This is the visible sink area where you wash your hands and face.

2. Faucet: The fixture that delivers water into the basin. It may have one handle or two handles to control temperature and flow.

3. Drain opening: The hole at the bottom of the basin where used water flows out.

4. Drain assembly: The parts beneath the drain opening that carry water away. This usually includes the drain flange, stopper, and tailpiece.

5. P-trap: A curved pipe under the sink that holds a small amount of water to stop sewer gases from coming back up through the drain.

6. Supply lines: Flexible pipes that bring hot and cold water from the wall to the faucet.

7. Shut-off valves: Small valves near the wall that let you turn off the water to the sink for repairs or emergencies.

8. Overflow opening: A small opening near the top of some sinks that helps prevent water from spilling over the rim. It connects to the drain system.

9. Countertop or vanity: The surface or cabinet that supports the sink. In many bathrooms, the sink is mounted into or on top of a vanity.

10. Mounting hardware and sealant: Clips, brackets, and caulk used to secure the sink and keep water from leaking around it.

Together, these parts let the sink hold water, provide running water, drain properly, and stay securely installed.

Turn off the water if needed and put a bucket under the sink. Open the cabinet and look under the drain. Most bathroom sink stoppers are connected by a pivot rod, a lift rod, and a horizontal pivot arm.

First, find the retaining nut on the drain body where the pivot rod enters. Loosen it by hand or with pliers and pull the pivot rod out. Next, remove the stopper from the top of the sink by lifting it out of the drain opening. If it’s stuck, wiggle it gently while pulling up.

Take the old stopper to a hardware store if you need an exact match. Install the new stopper by placing it into the drain opening so the hole or hook lines up with the pivot rod opening. Slide the pivot rod back into the drain body and through the stopper’s hole. Tighten the retaining nut snugly, but not too hard.

Test the stopper by moving the lift rod up and down. If it doesn’t seal or lift properly, adjust the position of the pivot rod or the clip connecting the lift rod and pivot arm. You may need to loosen and reposition it slightly.

If the stopper still leaks, clean the drain seat and the stopper with vinegar or a non-abrasive cleaner. If the rubber gasket or drain assembly is worn out, replacing the whole drain assembly may work better.

Finally, run water and check for leaks under the sink. Tighten any drips carefully.

Most bathroom sinks use a 1 1/4-inch drain, which is the standard size for the drain opening and most pop-up drain assemblies. That’s the size you usually need for a typical lavatory sink.

However, the drain size you need depends on the sink and the plumbing connections:

• Standard bathroom sinks: 1 1/4-inch drain
• Some newer or larger sinks: 1 1/2-inch drain
• Wall drain or trap connection: often 1 1/4-inch or 1 1/2-inch depending on the trap and pipe setup

The important thing is to match these parts:

1. Sink drain opening size
2. Pop-up drain or drain assembly size
3. P-trap and wall pipe size

If you’re replacing an old drain, measure the existing drain opening and the pipe going into the wall before buying parts. If your sink has an overflow hole, you also need a drain assembly designed for overflow sinks. If it has no overflow, get a non-overflow drain.

If you’re unsure, the safest bet for most bathroom sinks is a 1 1/4-inch drain assembly. If the sink came with specifications, follow the manufacturer’s listed drain size.

If you want, I can also help you figure out the exact drain size from a photo or by measuring your sink.

First, turn off the water supply valves under the sink. Open the faucet to drain any remaining water, and plug the drain so small parts don’t fall in.

Identify where it leaks:

• From the spout when off: usually a worn cartridge, valve seat, or washer.
• Around the handle: often an O-ring or packing nut.
• From the base: likely a gasket or loose mounting.

Remove the handle. This may require a small set screw hidden under a cap. Then take out the cartridge, stem, or valve assembly, depending on faucet type. Keep the parts in order or take a photo first.

Inspect the rubber washers, O-rings, and cartridge. If they look cracked, flattened, or mineral-stained, replace them with exact matches from a hardware store. Clean any mineral buildup with vinegar and a cloth. If the valve seat is corroded, replace it if possible.

Before reassembling, apply a little plumber’s grease to O-rings and moving parts. Reinstall everything snugly, but don’t overtighten. Turn the water back on slowly and test for leaks. If it still drips, the cartridge may be the wrong size or the valve body may be damaged.

If you see heavy corrosion, stripped threads, or the leak is coming from inside the wall, it may be better to replace the faucet or call a plumber.

A pop-up drain and a regular drain differ mainly in how they open, close, and are operated.

A pop-up drain has a built-in stopper mechanism that lets you open or seal the drain without removing a plug by hand. It is usually controlled by a lever behind the faucet, a knob, or a push mechanism. When activated, the stopper moves up or down inside the drain body, allowing you to fill the sink or let water out. Pop-up drains are common in bathroom sinks because they are convenient for washing, shaving, or filling the basin.

A regular drain is a simpler, open drain that does not include a built-in stopper mechanism. Water flows through it continuously unless you place a separate plug or stopper in the sink. It has fewer moving parts, so it is generally simpler, cheaper, and easier to maintain. Regular drains are often used in utility sinks, some bathroom sinks, and other fixtures where sealing the drain is not important.

In short, the key difference is that a pop-up drain includes an integrated, controllable stopper, while a regular drain is just a basic opening for water to pass through. Pop-up drains offer more convenience, but regular drains are simpler and less likely to need repairs.

The best materials for bathroom sink parts and accessories depend on durability, water resistance, appearance, and maintenance.

For faucets and drain parts, brass is usually the best choice. It resists corrosion, lasts a long time, and handles constant water exposure well. Stainless steel is another excellent option because it is strong, rust-resistant, and easy to clean. For a more budget-friendly choice, high-quality plastic or ABS can work for some internal parts, but it is less durable than metal.

For sink bowls, ceramic and vitreous china are the most popular because they are smooth, stain-resistant, easy to clean, and affordable. Porcelain-coated cast iron is very durable and attractive, but it is heavy. For a modern look, solid surface materials and tempered glass are also used, though they may need more care to avoid scratches or chips.

For accessories like soap dispensers, towel rings, and toothbrush holders, stainless steel is one of the best materials because it resists moisture and matches most bathroom styles. Chrome-plated metal is also common because it looks polished and is easy to maintain. For decorative accessories, brass, bronze, and matte black finishes can add style, but the base material should still be corrosion-resistant.

For sink seals and washers, silicone and rubber are best because they create a watertight fit and withstand moisture and temperature changes.

Overall, stainless steel, brass, ceramic, and silicone are among the best materials for bathroom sink parts and accessories because they combine durability, water resistance, and ease of maintenance.

Choose bathroom sink accessories by matching fit, function, material, and style.

First, check your sink type and size. A countertop sink, pedestal sink, vessel sink, or wall-mounted sink may need different accessories. Measure the bowl, faucet holes, drain opening, and the space around the sink so items like soap dispensers, trays, and organizers do not crowd the area.

Next, decide what you actually need. Common accessories include a soap dispenser, toothbrush holder, tumbler, sink caddy, drain stopper, basin strainer, and faucet aerator. If your countertop is small, choose compact or wall-mounted items. If several people share the bathroom, look for larger or multi-slot organizers.

Material matters for durability and cleaning. Stainless steel, ceramic, glass, brass, and high-quality plastic are popular options. Pick moisture-resistant, rust-proof materials since bathrooms are humid. Easy-to-clean finishes help reduce water spots and soap buildup.

Match the accessories with your sink and bathroom style. For a modern look, use sleek chrome, matte black, or minimalist shapes. For a classic or warm look, ceramic, brushed nickel, or brass may suit better. Coordinating with your faucet and hardware creates a polished appearance.

Also consider maintenance and usability. Choose accessories that are stable, easy to refill, and simple to remove for cleaning. Non-slip bases and weighted dispensers are helpful.

Finally, set a budget and prioritize quality for items you use daily. A few well-chosen accessories that fit properly and last longer are better than many mismatched ones.