Milling Rounded Edges in Wood - How to Perfectly Round Wood Edges in 5 Steps
Rounding Edges with a Router or router table – Step by Step
Rounding off edges is one of the most common tasks in a woodshop: It not only improves the appearance of furniture and workpieces, but also makes them safer and more comfortable to handle. Sharp edges are processed in such a way that they are less pointed and therefore less likely to cause injury.
This 5-step guide shows you how to round off wood edges using a hand router and the router table —from choosing the right tool to setting the cutting depth and finishing up.
Milling a rounded edge on the RUWI router table
Table of Contents
- Key Facts at a Glance
- Preparation
- Instructions for Milling a Radius
- Tips for Improving Milling Results
- Machines and Tools for Cylindrical Milling
- What other types of circular milling are there?
- FAQ
Key Facts at a Glance
Preparation: Decide which machine and which rounding cutter are best suited for your project.
Procedure: Make sure the milling depth, speed, and direction are set correctly.
Finishing: Be sure to set aside enough time and have the right expertise for the finishing touches.
Preparation: What do I need to mill a rounded edge in wood?
Before you start cutting, make sure you've got four things sorted out: the machine, the cutting tool, the clamping setup, and safety precautions.
Router or router table: Both machines are suitable for rounding edges. Which one you choose depends on the workpiece: Anything you can carry to the machine goes into the router table; assembled parts and large panels are best handled by the hand-held router.
Router Bit: Choosing the right router bit is crucial for routing a curve into a piece of wood. Use different router bits in various sizes to achieve the desired curve—from small chamfers to large radii. There are also specialized tools, such as the R2.5 double-rounding and chamfering router bit, which allows you to machine two edges at the same time.
Clamping device: If you’re using a hand-held router, you’ll need clamping tools such as a Bessey 200-mm screw clamp with clamping bolt or clamping jaws to ensure the workpiece is held securely and precisely. On the router table it’s the opposite: There, the workpiece rests on a large surface area and is guided by the stop, while both hands remain on the wood. The tool guard and guide ring make even the smallest parts manageable.
Safety Equipment and Dust Extraction: Safety goggles and ear protection are required when using the router; for dust-intensive work—including later sanding—you’ll also need a dust mask. And be sure to connect the dust extraction system: Wood dust irritates the respiratory tract, and dust from oak and beech is considered carcinogenic. To find out which dust collector is suitable for this, see the article “Extracting Wood Dust.”
Before you start, check the condition of the tools: A sharp, properly clamped milling cutter is crucial for both the result and safety.
List of Materials
- Non-slip or anti-tip mat or work table
- Workpiece to be rounded
- Material for a test milling operation
- Sandpaper
Tools
- Handheld router or router table
- Radius cutters, quarter-round cutters, or rounding cutters
- Clamping Tools
- Sandpaper or sanding block
- Ventilation, PPE (Personal Protective Equipment)
Instructions for Milling a Radius
Five steps take you from selecting the right radius to the finished edge.
Step 1: Determining and Setting the Desired Radius Size
The size of the rounding depends on aesthetics and function. A common minimum requirement is an R2 rounding cutter to create a chamfer and soften sharp edges. Where the edge is gripped by hand—such as on handrails, grab bars, or seating furniture—a larger radius (≥ R5) is recommended: it fits more comfortably in the hand, and the edge is less likely to splinter. On furniture fronts, however, aesthetics are usually the deciding factor.
Make sure the machine is turned off and unplugged while you are using the tool. When clamping it in place, make sure the rounding tool is seated all the way to the mark on the shank in the collet .
Selection of Milling Tools for Rounding
Step 2: Setting the Milling Depth
If you want to round off curved edges, we recommend using a rounding cutter with a guide ring. The guide ring scans the contour and guides the router bit cleanly along the curved edge. For straight workpiece edges, you can also use a router bit without a guide ring by guiding the workpiece along the stop rail of the router table or the rip fence of the hand-held router. In both cases, however, it is important to set the cutting depth correctly.
The radius of the router bit should be flush with the machine table. If the router bit protrudes too far, a step will form; if it doesn’t protrude far enough, a small edge will form at the transition. You can adjust the cutter height using a digital depth gauge or a test piece until the outermost edge of the cutter just touches the wood surface. A test cut will show you whether you have the correct setting.
Tip: Sometimes it can be a good idea to intentionally set the rounding cutter a little deeper to achieve a special decorative edge look: the “German Stab,” a rounded edge with a small step. Try out different settings to find the look you want.
Step 3: Clamping and Safety Devices
When working with a hand router, the workpiece must be securely clamped—the machine moves, not the wood. Use screw clamps, quick-release clamps, or clamping jaws. To prevent indentations in the wood, place a shim between the workpiece and the clamp. For heavy workpieces, it may be sufficient to place them on a support rail with a non-slip surface. Then you can rout all around it without a clamp getting in the way. However, make sure the workpiece doesn’t slip.
On the “ router table ,” however, the workpiece is guided rather than clamped. This machine includes a tool guard and a clamping device. Plastic spacer rings minimize the gap between the workpiece and the rounding cutter and maximize the contact area—this allows even very small parts to be rounded safely on the “ RUWI ”router table .
Routers for rounding the edges of workpieces
Step 4: Mill the rounding
Once you have carefully adjusted the milling depth and installed the clamping or safety devices, you can begin the actual milling process. First, check that the correct speed is set, and then turn on the machine.
When feeding by hand, milling is performed in a counter-feed motion: The cutting edge moves toward the feed at the point of contact, the cutting force acts against the direction of your push, and the workpiece remains under control. In a co-feed motion, the tool pulls the workpiece toward it on its own—this self-feed cannot be controlled by hand.
For more on this, see the article " Counter-rotation Milling."
Guide the router bit along the edge with even pressure and at a steady speed. When using a hand-held router, it’s especially important to keep the router from tilting. With the router table , the workpiece rests on a large surface area, so you guide the workpiece (rather than the machine).
Tip: Using a suitable rounding cutter on the router table , you can turn a square strip into a round rod—using the clamping device, not freehand. See the FAQ below for information on how the strip dimensions and cutter radius relate to each other; a video on this topic is available under“Milling Round Rods.”
Milling Curves with a Handheld Router
Step 5: Checking and Finalizing
Carefully inspect the milled workpiece for irregularities or unevenness. Make sure the curve is smooth and even. If you see irregular indentations (planer marks), the feed ring may be dirty, or the feed rate may have been too high. Reducing the feed rate slightly may help.
You can carefully smooth out minor irregularities and the transition from the curve to the flat surface using sandpaper with a grit of 120 to 180.
Once the milling work is complete, you should clean the milling tool and inspect it for any damage. Have the tool sharpened if necessary.
Tips for Improving Milling Results
- Practice makes perfect: Start by using the router on a practice piece to get a feel for the machine before you tackle your final project.
- Milling cutter quality: Pay attention to the cutting material and the ability to resharpen—for tools used frequently, a resharpenable milling cutter or a version with indexable inserts is a worthwhile investment.
- Adequate contact surface: For larger workpieces, a table extension help increase the contact surface.
- Prevent tipping: Increase the contact surface of a hand-held router by screwing a Plexiglas plate (about 25 × 25 cm) under the base. Or place material of the same thickness parallel to the edge so that the router rests stably.
- Multiple passes: For large curves, it is better to mill in several passes to minimize chip removal and achieve a cleaner finish.
- Care and Maintenance: Clean the router bit and router after each use, ensure the cutting edges are sharp, and follow your machine's instruction manual.
Machines and Tools for Cylindrical Milling
Choosing the right woodworking machine depends on the type and size of the project, as well as the desired profile size and precision:
- Hand-held routers: For assembled parts, large panels, and on-site work. This includes the edge router, which is specifically designed for edge finishing.
- router tables: For production runs and any application where the settings need to remain consistent across many parts. Used in woodworking shops, training facilities, and industrial settings. The RUWI router table bears the GS mark (DGUV Test) and has been tested for wood dust; the protective hood, tool cover, and insert ring are included with the unit.
- Stationary bench-top milling machines or CNC milling machines: For large profiles, complex or high-volume milling jobs.
- Sanding machines (such as belt sanders): Suitable for rounding edges, but require practice. Good for organic shapes.
- Hand plane: If you prefer the traditional approach and have the necessary skill, you can also plane a curve by hand.
RUWI router tables , Classic Performance, and Premium
Edge Grinding Machine as an Alternative to Milling
What other types of circular milling are there?
In addition to the common “edge rounding,” there are other types of round milling:
- Rounding a corner: You round the outer corners of a surface, such as a tabletop.
- Circular milling instead of drilling: If you want to mill a hole in a workpiece—for example, for a round sink cutout in a kitchen countertop.
FAQ
Why does the rounded edge have brown spots or scorch marks in some places?
This can be caused by excessive spindle speed, too slow a feed rate, or a dull cutter. Excessive friction generates heat, which can burn the wood. Therefore, make sure to use the appropriate spindle speed, a brisk feed rate, and sharp tools.
Why is the milled rounded profile uneven or rough?
If the guide ring is dirty or the workpiece wasn't guided properly, so-called planing marks or unevenness may occur. An excessively high feed rate can also cause chatter marks. Clean the guide ring, adjust the speed, and ensure the workpiece is guided securely. If there is only slight roughness, you can finish the surface with fine-grit sandpaper.
How can I make a round bar?
To make a round rod, you’ll need a square strip whose cross-section matches the radius of your router bit. Example: A round rod with a 16 mm diameter requires an R8 quarter-round router bit and a 16 × 16 mm strip. For an R12.7 mm bit, you’ll need a 25.4 × 25.4 mm strip (2 × 12.7 mm). This is easier to do on a router table with a clamping device than freehand with a handheld router.
What is the correct rounding radius for my workpiece?
That depends on the look and function you're going for. A small radius (such as R2) looks subtle, while a larger radius (≥ R5) makes the edge easier to grip. It's best to test a sample piece to see which one you like best.
How do I set the correct speed for my router?
Never exceed the maximum speed (see the specification on the cutter). Within this limit, the speed depends on the cutter’s diameter: the larger the cutter, the lower the speed. Common rounding cutters have a diameter of less than 30 mm—for these, you can run at high speeds, up to about 24,000 rpm. For diameters between Ø 30 and 50 mm, about 16,000 to 18,000 rpm is a good guideline; even larger diameters fall into the “ router table.” Too high a speed with too low a feed rate leads to heat and scorch marks—softwoods and resins-rich woods are particularly susceptible to this. Conversely, a feed rate that is too high relative to the speed leaves visible planing marks. It’s best to test different settings on a scrap piece of wood. You can find more information on speed, feed rate, and depth of cut in the article on routing.
