If you’ve spent any time on the woodworking side of the internet, you’ve probably heard someone warn you about climb cutting with a router and how dangerous it can be. There’s truth in that warning, but if the technique is used correctly, it can be an asset in woodworking. Knowing when to use it is one of those things that separates a clean edge from tear-out or fuzzy edge profiles.
What Climb Cutting Actually Means
When using a handheld router, router bits spin in a clockwise direction when you’re looking down at it from above. How you move the router, or the workpiece, relative to that spin is what determines whether you’re cutting conventionally or climb cutting.
Conventional cutting means you’re feeding the bit against its rotation. The cutting edge meets the wood head-on, which gives you resistance and control. Climb cutting flips that. You’re feeding in the same direction the bit is already spinning, so instead of biting into the wood, the bit climbs up onto it. Think of it as a tire on pavement; the tire is pushing against the pavement, driving you down the road. When climb cutting, the router bit touches the wood, and it takes off, driving you down the board. If you take too big a cut, you won’t be able to control the router, and it can fly out of your hand as it races down the board.
That’s why it’s dangerous, and it’s the reason conventional cutting is taught as the default. In a climb cut, the bit can grab the material and yank the router (or the workpiece, if you’re at a router table) along with it, faster than you’re feeding and with no warning. On a handheld router, that means it can suddenly lurch sideways and drag your hands with it. On a table, the workpiece can get torn right out of your grip.
Climb cutting is most dangerous on:
- Deep cuts, or removing a lot of material in one pass
- Hard or heavily figured wood
- Full-width cuts instead of a light skim
- Anything less than a solid grip and stable footing
None of that means climb cutting is off the table. You just need to know what you are doing.
Why I Use It
I use this technique on purpose, most often to prevent tearout. When the bit is feeding conventionally, it’s lifting fibers as it goes, and on figured wood, veneered plywood, or anywhere the grain reverses along a curve, that lifting action can blow out the edge right before you get to it. A climb cut works with the grain at the surface instead of against it, so the cut comes out cleaner. If you are familiar with hand planing techniques and planing the direction the grain lays down, climb cutting is a similar idea.
I’ll use it for:
- A light finish pass on figured stock like curly maple or walnut, where a conventional pass would tear out
- The section of a profile where the grain direction flips, rather than fighting it end to end
- Cleaning up the exit side of a cut on cabinet-grade plywood or veneer, where chipping is the main risk
- One final very shallow pass to clean up an edge profile so it comes out as smooth as possible, reducing the amount of sanding I have to do after routing.
To keep it safe, I take a shallow pass, usually just skimming the last sixteenth of an inch or less rather than removing full depth in one go. Slow feed rate, sharp bit, firm two-hand grip, solid stance before I ever touch the router bit to the wood.
Feed Direction, Broken Down
One thing to note: the “correct” direction isn’t the same in every situation. It depends on whether you’re on an outside edge, an inside edge, or a table.
Outside edge (handheld). Think of routing around the outside of a tabletop or a template. As a rule of thumb, you move left to right as you face any given edge, working counterclockwise around the whole perimeter.
Inside edge (handheld). Routing inside a frame or cutouts flips your direction to clockwise. Same bit, same spin direction, but the material’s relationship to the bit has reversed, so the safe feed direction reverses with it.
Router table. Since the wood is moving rather than the tool, you want to feed from right to left, standing in your normal position facing the fence.
Reverse any of those three, and you are now climb cutting, whether you meant to or not.
You Can Get More Aggressive On A CNC
On the CNC, software lets you set climb or conventional milling directly on each toolpath, and because the machine holds feed rate steady and the workpiece is clamped down solid, climb milling is often my preference for most operations. The edge quality is better, and the kickback risk that makes climb cutting dangerous by hand isn’t a factor when the router is held in a gantry instead of my hands.
Climb cutting isn’t something to avoid outright, and it isn’t something to reach for carelessly either. Know which direction you’re feeding relative to the bit, take it slow when you’re doing it on purpose, and it becomes one more tool for getting a clean edge when routing.
I’m the owner of Benham Design Concepts, a mixed media art studio where I design and build custom furniture and other works of art using wood, glass, stone, and various metals.
In this blog, I talk about the art I create, my journey, and the things I learn along the way.