Toner Cartridge vs Drum Unit

The toner cartridge is the container that holds the toner powder. The drum unit is an electrically charged cylinder that transfers that toner powder to paper to create text and images.

Both of these components are essential for producing a print. Depending on what printer you own, you might be used to replacing your drum unit occasionally, or you may have never had to replace a drum unit.  So, why the inconsistency?  It is all contingent on the design of your printer. A drum unit can be incorporated with the toner cartridge or sold separately as a single unit, depending on the consumable requirements of your printer.  Laser printers and their consumables vary across printer models. Some printers only need you to replace the toner cartridge, and others require that you regularly replace both the toner cartridge and the drum unit.  Consult your printer’s user manual to determine what consumables are appropriate for your machine.

Most printers use toner cartridges with the drum unit built into the cartridge. If you own an HP laser printer, for example, the drum unit is likely incorporated into the toner. Therefore, there is no need to replace the drum separately. Every time you buy a new toner for that HP printer, you are replacing the drum.  Some printers, like most Brother laser printer models, use a separate toner and drum unit. In this case, the drum unit is not built into the toner, and therefore, must be replaced. Separate drum units last quite a bit longer than a toner cartridge and typically should be replaced after the use of 3-4 toners. Your printer should inform you when it’s time to replace the drum, but you can usually tell your drum is on it’s last legs if you start to see black spots or lines across the page.