Milling roundings in wood - perfect rounding of wooden edges in 5 steps
Here's how to do it easily: Perfectly milled rounded edges using a router or router table
Rounding off edges is one of the most common processes in woodworking, which not only improves the appearance of furniture and workpieces, but also makes them safer and more pleasant to handle. Sharp edges are processed in such a way that they are less pointed and therefore less prone to injury.
This 5-step guide shows you how to professionally round wood edges with a router - from preparation to implementation. Whether you are a hobby craftsman, woodworker or a professional such as a carpenter or joiner, you will find the information you need here.
Milling curves on the RUWI milling table
Table of contents
- Important facts at a glance
- Preparation
- Milling rounding instructions
- Tips for improving the milling result
- Machines and tools for circular milling
- What other types of circular milling are there?
- FAQ
Important facts at a glance
Preparation: Decide which machine and which rounding cutter is best suited to your project.
Execution: Ensure that the milling depth, speed and milling direction are set correctly.
Post-processing: Allow sufficient time and the right know-how for the finish.
Preparation: What do I need to mill a rounding in wood?
Circular milling opens up many possibilities for you to change the look and feel of your workpiece. Our step-by-step guide will accompany you from preparation to implementation.
Router or router table: Both machines are suitable for rounding off edges. Which one you choose depends on your personal preference and the specific requirements of your project.
Milling tool: Selecting the right milling tool is crucial for milling a rounding on a wooden part. Use different milling heads in different sizes to achieve the desired rounding - from small edge breaks to large radii. There are also special tools such as the R2 double rounding and chamfering cutter, which allows you to process two edges at the same time.
Clamping device: If you are using a manual router, clamping devices such as a Bessey 200 mm screw clamp with clamping bolts and clamping claws are essential for positioning your workpiece securely and precisely. An even safer method is to use a router table, as you always have the tool in view. A tool cover also allows you to safely round off even the smallest parts.
Safety equipment: Working with a router or a router table requires the proper protective gear. Therefore, always wear safety goggles and ear protection. Depending on the material and tool, a dust mask may also be advisable.
Make sure that all tools and materials are in perfect condition before you start routing. Thorough preparation not only ensures a better result, but also your safety during the work process.
Material list
- Non-slip or anti-tip mat or workbench
- Workpiece to be rounded
- Material for test milling
- Sandpaper
Tools
- Handheld router or router table
- Radius cutters, quarter-round cutters, or rounding cutters
- Clamping tools
- Sandpaper or sanding block
- Extraction, PPE (personal protective equipment)
Milling rounding instructions
In this step-by-step guide, we will show you how to create perfect curves in your workpiece using a router or router table. From selecting the right radius size to checking and post-processing the routing result, we will guide you through the entire process and help you achieve optimum results.
Step 1: Determining and setting the desired radius size
You should choose the size of the rounding depending on the look and functionality. A minimum requirement is often a rounding cutter R2 as an edge break to soften sharp edges. For items such as children's toys, a larger radius (≥ R5) is recommended to make the toy more tactile and easier to grip. This also reduces the risk of injury and increases the lifespan as small parts are minimized from splintering.
Make sure that the machine is switched off and disconnected from the power supply while you are inserting the tool. When clamping, make sure that the rounding tool is seated in the collet up to the mark on the shank.
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 cutter cleanly along the curved edge. For straight workpiece edges, you can also use a cutter without a guide ring by guiding the workpiece along the fence of the router table or the rip fence of the hand router. In both cases, however, it is important to set the cutting depth correctly.
The radius of the milling cutter should be flush with the machine table. If the cutter protrudes too far, a shoulder will form; if it protrudes too little, a small edge will form at the transition. You can adjust the cutter height using a digital setting gauge or on a test piece until the outermost edge of the cutter just touches the wood surface. A test routing will show you whether you have the right setting.
Tip: Sometimes it can be effective to intentionally set the rounding cutter a little deeper to achieve a specific decorative edge effect (the "German edge"). Try out different settings to find the look you want.
Step 3: Clamping and protection devices
To round the edges of the workpiece safely and precisely, you should clamp it well. Use screw clamps, quick clamps or clamping claws. To avoid pressure marks in the wood, place a support between the workpiece and the clamp. For heavy workpieces, it may be sufficient to place them on a support rail with an anti-slip coating. Then you can mill all around without a clamp getting in the way. However, make sure that the workpiece does not slip.
If you’re rounding the edges of wood on a router table, you should use a tool guard. With the RUWI router table, you can safely round even tiny pieces, such as wooden jewelry. Plastic spacer rings minimize the gap between the rounding bit and the workpiece and maximize the contact surface.
Note: Be sure to use a dust extraction system and always wear your PPE (ear protection, dust mask) when working with machines and tools.
Router used for rounding the edge of a workpiece
Step 4: Mill the rounding
Once you have carefully set 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. As a rule, you should mill in reverse; only rarely and with great caution should you mill in forward direction. Learn about the differences between forward and reverse milling to understand the advantages and disadvantages.
You can find more information on milling processes in our encyclopedia article on up-cut milling.
Guide the router tool along the edge with even pressure and speed. With a manual router, it is particularly important that the router does not tilt. The workpiece rests on a large surface on the router table so that you guide the workpiece (instead of the machine).
Tip: With the right rounding cutter on your router table, you can easily turn a square strip into a round rod. We recommend watching a video on“routing round rods.”
Milling curves with a hand-held router
Step 5: Checking and post-processing
Check the milled workpiece carefully for irregularities or unevenness. Make sure that the rounding is even and clean. If you see irregular indentations (planing strokes), the thrust ring may be dirty or the feed speed may have been too high. A slightly lower speed may help.
You can carefully smooth out minor imperfections and the transition from the curve to the flat surface using sandpaper with a grit of 120 to 180. Be sure to wear a dust mask to protect yourself from wood dust.
After completing the milling work, you should clean the milling tool and inspect it for any damage. If necessary, have the tool sharpened.
Tips for improving the milling result
- Practice makes perfect: First mill a practice piece to get a feel for the machine before tackling your final project.
- Cutter quality: A high-quality cutter can make a big difference. Look for durable cutting edges for better results.
- Sufficient support surface: For larger workpieces, a table extension can help to increase the support surface.
- Prevent tipping: Increase the contact surface of a hand-held router by screwing a sheet of Plexiglas (about 25×25 cm) under the base. Or place a piece of 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 two or three passes to minimize chip removal and achieve a cleaner finish.
- Care and maintenance: Clean the milling cutter and milling machine after each use. Make sure they are sharp and read the operating instructions to ensure that everything runs smoothly.
Machines and tools for circular 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: Ideal for smaller projects or when you want to work flexibly. They’re portable, making them perfect for use on construction sites, for example. This category includes edge routers and stick routers, which are specifically designed for edge finishing.
- Router tables: Ideal for larger projects or when you need consistent precision. They’re used by DIY enthusiasts, woodworkers, and educational institutions alike. With professional solutions like the RUWI router table, you can work safely and quickly.
- Bench-top milling machines or CNC milling machines: For complex or high-volume milling jobs—especially in professional settings.
- 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.
The RUWI Performance and Premium milling tables
Edge sander 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 rounding:
- Rounding a corner: You round the outer corners of a surface, such as a tabletop.
- Milling instead of drilling: If you want to mill a hole in a workpiece, for example, to create a round sink cutout in a kitchen countertop.
FAQ
Why does the edge have brown spots or scorch marks in some places?
This can be caused by too high a speed, too low a feed rate or a blunt milling cutter. Excessive friction leads to heat development, which can burn the wood. Therefore, make sure that the speed is adjusted, the feed rate is fast and the tools are sharp.
Why is the milled rounding profile uneven or rough?
If the thrust ring is dirty or the workpiece has not been clamped correctly, so-called planing strokes or unevenness can occur. Too high a feed speed also leads to chatter marks. Clean the thrust ring, adjust the speed and clamp the workpiece firmly. If the roughness is only slight, you can rework with fine sandpaper.
How can I make a round bar?
To create a round rod, you’ll need a square strip whose cross-section matches the radius of your router bit. For 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 hand 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 table?
The maximum speed must never be exceeded (see information on the milling cutter). Soft woods can be milled at a lower speed, hard woods often require more power. Too high a speed leads to heat and burn marks, too low a speed leads to chipping. It is best to try out different settings on a scrap piece.
