A planer is a woodworking tool that shaves wood to a uniform thickness, turning rough or uneven boards into smooth, dimensioned lumber. Whether you’re working with a hand-held model on a job site or a benchtop machine in your shop, the core job is the same: remove material from a board’s surface so it comes out flat, smooth, and exactly the thickness you need.
How a Thickness Planer Works
A stationary thickness planer (sometimes called a “thicknesser” in the UK and Australia) uses a rotating cutterhead positioned between two feed rollers. You set the desired thickness, feed the board in, and the rollers push it through at a consistent speed while the cutterhead shaves material off the top surface. The flat bed underneath acts as a reference, ensuring the planed face ends up parallel to the bottom face.
Most consumer planers remove up to 1/8 inch of material per pass on wider boards. You work in multiple light passes, lowering the cutterhead slightly each time, until the board reaches your target thickness. Trying to take too much off in a single pass strains the motor, dulls the blades faster, and leaves a rougher surface.
What Woodworkers Actually Use It For
The most common use is turning rough-sawn lumber into boards you can actually build with. Lumber from a sawmill or hardwood dealer is often uneven, cupped, or varying in thickness from one end to the other. A planer solves that. It’s also the tool you reach for when you need several boards at exactly the same thickness for a tabletop, drawer sides, or panel glue-ups.
Beyond basic thicknessing, planers are used to reclaim old wood by cleaning up weathered or painted surfaces, to thin stock down for projects like jewelry boxes or thin drawer bottoms, and to smooth boards that are too wide or awkward to run over a table saw. If you’re building anything from furniture to cutting boards to cabinetry, the planer is what gives your lumber consistent, predictable dimensions.
Planer vs. Jointer: Why You Need Both
This is one of the most common points of confusion. A jointer flattens one face of a board and squares up one edge. A planer makes the opposite face parallel to the first and brings the board to a specific thickness. They do different jobs, and one can’t fully replace the other.
Here’s the key distinction: if you run a warped board through a planer without jointing it first, the feed rollers press the warp flat against the bed, the cutterhead planes the top, and then the board springs back to its warped shape, now just thinner. The planer copies whatever the bottom face looks like. That’s why the standard workflow is to flatten one face on the jointer first, then send it through the planer with the jointed face down. The jointer makes wood flat. The planer makes wood parallel and thinner.
Types of Planers
Benchtop Thickness Planers
These are the most popular choice for home workshops. Sometimes called “lunchbox” planers because of their compact size, they handle boards up to about 12 or 13 inches wide and do a solid job of thicknessing stock for furniture and small projects. They’re portable enough to store on a shelf when not in use.
Electric Hand Planers
A handheld electric planer is more of a construction tool than a fine woodworking tool. Carpenters use them to shave down a door that’s sticking, level floor joists before laying plywood, or knock off a high spot on a rafter. They’re good for quick, localized material removal, but they won’t give you the precision or consistency of a stationary planer. Think of them as a powered rough-shaping tool.
Manual Hand Planes
Traditional hand planes predate power tools by centuries and are still widely used. They excel at fine smoothing, fitting joints, chamfering edges, and working small or delicate pieces where a power planer would be overkill. Many woodworkers use hand planes to finish surfaces after running them through a thickness planer, removing the subtle milling marks the machine leaves behind.
Industrial Metal Planers
In metalworking, a planer machine creates flat or angled surfaces on large, heavy metal components. The workpiece sits on a table that moves back and forth beneath a stationary cutting tool. These machines are used in automotive manufacturing, aerospace, and heavy fabrication to produce parts like engine blocks and molds. Some are large enough to require a pit in the shop floor to accommodate the workpiece.
Straight Blades vs. Helical Cutterheads
Traditional planers use straight knives that contact the full width of the board at once. They work fine but are louder, create more vibration, and are more prone to tearing out wood grain, especially on figured or interlocking-grain species.
Helical cutterheads use dozens of small carbide inserts arranged in a spiral pattern. Instead of chopping straight across the grain, they take a shearing cut. The practical differences are noticeable: less noise, less vibration, smoother surfaces, and significantly reduced tear-out. The carbide inserts also last much longer than straight steel knives. If one insert gets a nick, you simply rotate it to a fresh edge rather than replacing or resharpening the entire blade. The upfront cost is higher, but the long-term cost of ownership is often lower.
How to Avoid Snipe
Snipe is the single most common planer frustration. It shows up as a shallow dip or gouge at the beginning or end of a board, typically in the last few inches. It happens when the board is only under one feed roller instead of two, allowing the cutterhead to bite slightly deeper.
A few practical fixes make a big difference. Using infeed and outfeed support tables keeps the board level as it enters and exits the machine. Feeding boards end to end, so each one supports the next, eliminates the moment where only one roller has contact. You can also place a sacrificial scrap board at the front and back of your batch to absorb the snipe instead of your good stock. Keeping blades sharp and rollers properly aligned also helps, since dull blades and misaligned rollers make snipe worse.
Tips for Better Results
Always plane with the grain. If you feed a board so the grain angles upward into the cutterhead, you’ll get tear-out: rough, splintery patches where the blade catches and lifts wood fibers instead of shearing them cleanly. Flip the board around and the problem usually disappears.
Take light passes rather than aggressive ones. Removing 1/32 to 1/16 inch per pass produces a cleaner surface and puts less stress on the machine. For hardwoods or wide boards, even lighter passes are better. If the planer bogs down or the surface comes out with visible scallops, you’re taking too much at once.
Dust collection matters more than many beginners realize. Planers produce enormous volumes of chips and fine dust, especially when working with hardwoods or engineered materials like particleboard. A good dust collection hookup keeps the machine running efficiently and the air in your shop breathable. Without it, chips can pack around the cutterhead and affect surface quality.