Tub drain assemblies are commonly made from one of three different pipe materials: brass, ABS (acrylonitrile butadiene styrene) plastic, or PVC (polyvinyl chloride plastic). Tub drain assemblies can be joined with slip fittings (brass, ABS, or PVC), or with solvent-glued fittings (ABS or PVC only). When using ABS or PVC that will be joined with solvent-glued fittings, make sure to stick with the same type of plastic found in the rest of the drain system. ABS and PVC should not be glued to one another. If you will be using slip joints to connect the pieces, then it’s fine to use different materials. Finally, you will have a choice in what kind of pop-up drain mechanism you want. Options include spring-loaded toe-touch stoppers, push/pull stoppers, or lever-operating stoppers. Here are the variations in bathtub drains to help you make the right selection for your needs. PVC is the now plastic drain pipe of choice for most professional plumbers.