Drain snakes come in several different types, ranging from simple handheld models to powerful motorized augers. The reason for the variety is that there are different types of drains: sink drains, toilet drains, house drains, sewer drains, etc. While a plumber might have all of them, you'll likely need on only one or two, unless you want to rent a big auger for cleaning a sewer drain.
A toilet auger, also called a closet auger, is an inexpensive manual (not motorized) snake made specifically for toilet stoppages. This is what you use if you can't clear a toilet clog with a plunger or if you think something is stuck inside your toilet (such as a sponge or a small toy).
A toilet auger has a long metal tube with a bend at one end. A cable runs through the tube and is turned with a handle by the user. The "business end" of the cable has a corkscrew-like tip that threads its way into clogs and soft objects so you can pull them back out of the toilet. The bend in the auger fits into the hole in the bottom of the toilet bowl and gets the cable end close to the trap, where clogs most likely occur. That's why toilet augers are more effective on toilets than standard snakes.
A standard household drain snake, sometimes called a drum snake or top snake, is the smallest of the drain-clearing augers. It is primarily used for clogs in tubs, showers, bathroom sinks, washing machines, and sometimes kitchens sinks. Most have a 25- or 50-foot cable with a corkscrew tip for snagging debris. They come in many different shapes and sizes as well as manual and electric.
A drum snake has a cylindrical or bell-shaped drum into which the snake cable is coiled. Many also include a handle for supporting the tool and a rotating knob for turning the drum (and cable). Another type of standard snake is nothing more than a 25- or 50-foot cable with a tubular metal handle that slides along the cable and is tightened down to turn the cable.
Mini-Rooter or Medium Drain Machine
A mini-rooter (or medium drain machine) is a light-duty version of a sewer auger. It typically includes a 3/8-inch-diameter cable and should have at least 50 to 75 feet of cable length. It also has an electric motor that spins the cable and an assortment of interchangeable cutter heads for various types of clogs.
These snakes are great if you have a long kitchen or washing machine drain to clean out, or if you need to snake the drain from (or under) the kitchen or bathroom sink once you take off the trap. They can also be used to clear a kitchen or washing machine line from a roof vent. Do not use these machines for tub or shower stoppages because they can damage the trap under the tub or shower. While some mini-rooters come with cutter heads for 4-inch drain lines, usually these machines aren't powerful enough to clear difficult sewer drain clogs, like tree roots.
A sewer auger is a professional-grade drain machine used for clearing 3-inch and 4-inch drains and sewer lines, such as the buried drain running from a house to the city sewer main under the street. It has a heavy-duty electric motor that spins a large cage containing a 100-foot or longer cable. Cables are either 5/8 inch or 3/4 inch in diameter.
When plumbers are called to clear a house's sewer drain, this is what they bring. They don't bother with mini-rooters on standard 4-inch sewer lines. Plumbers have large, very expensive versions of these augers, but you can rent smaller units with 100-foot cables and 4-inch cutter heads. It takes a little practice to learn how to use a sewer auger effectively, but renting a machine for half a day is much cheaper than having a plumber or roto-rooter technician clear a drain.