Guides

How to Round Over Edges with a Router

Learn how to round over edges with a router: bit size, bearing setup, feed direction, and clean passes on hardwood or plywood.

Learning how to round over edges with a router is one of the fastest ways to make a project look finished. A round-over bit softens sharp corners, improves paint and finish adhesion, and makes tabletops, shelves, and cabinets safer to handle. This guide covers bit selection, bearing setup, climb-cut caution, and the light multi-pass habit that keeps tear-out off your show faces.

What a round-over actually does

A round-over bit cuts a quarter-circle radius along an edge. The bearing rides the face you leave as a reference, so the radius stays consistent as long as the bearing stays clean and the workpiece edge is straight. Common sizes are 1/8 in, 1/4 in, 3/8 in, and 1/2 in. Smaller radii look subtle on trim and boxes; larger radii suit thick tops and soft-touch furniture edges.

Tools and setup checklist

Router with a sharp round-over bit that matches your desired radius
Collet sized to the bit shank (1/4 in or 1/2 in)
Workpiece clamped solidly with the edge fully supported
Scrap of the same material for a test pass
Eye and hearing protection, dust collection if available
Optional: router table for short pieces or production runs

How to round over edges with a router

Choose radius and confirm the bearing

Match the bit radius to stock thickness and style. On 3/4 in stock, a 1/4 in round-over is a safe everyday choice; a 1/2 in radius needs enough thickness so you do not leave a knife edge. Wipe the bearing, spin it by hand, and confirm it turns freely. A sticky bearing burns the reference face and ruins the cut.

Seat the bit and set height on scrap

Insert the shank fully, then back it out slightly so the collet grips the shank, not the fillet. Tighten to the tool maker’s spec. Set bit height so the bearing rides the face and the cutter just kisses the edge at full radius. Make a short scrap pass, then adjust until the profile looks complete without cutting into the face.

Clamp and plan feed direction

Clamp the board so the edge hangs clear of the bench. For handheld work, move left to right when the router is between you and the edge in the usual orientation—against bit rotation so the cutter bites into the wood instead of climbing. Mark grain direction on figured hardwoods and plan to take a lighter first pass on end grain.

Take a light first pass, then finish

Start with a shallow cut or a partial radius if the bit allows. Keep the base flat and the bearing against the face. Feed at a steady pace—too slow burns, too fast leaves chatter. On end grain, reduce depth or speed and finish with a final light pass. Flip and repeat on the opposite face only if you want a bullnose-style edge.

Clean up and inspect

Brush dust from the radius and check for burn marks, ridges, or tear-out at corners. A quick sanding with a foam pad that matches the radius blends cutter marks without flattening the profile. If tear-out appears on plywood veneer, switch to a sharper bit, slow the feed, or back up the edge with sacrificial scrap.

Handheld vs router table

Handheld routing wins on long tabletops and installed workpieces. A router table is safer and more consistent for short rails, drawer fronts, and small boxes where the bit stays fixed and you feed the stock. On the table, use a fence when helpful, keep featherboards light, and never freehand small parts against a spinning round-over bit.

Tear-out and burn fixes

Dull carbide leaves fuzzy plywood and burn lines—replace or sharpen the bit
Climb-cutting a tiny skim pass can tame end-grain tear-out, but keep it controlled and shallow
Lower RPM on large diameters; many variable-speed routers run too fast for big round-overs
Support thin veneer with a backer board on the exit edge
Clean pitch from the bearing and cutters between hardwood sessions

When not to round over

Skip a heavy round-over on thin stock that would leave a sharp remaining edge. Avoid rounding edges that must stay crisp for joinery, edge banding glue lines, or hardware that needs a square reveal. For paint-grade cabinets, a small 1/8 in radius often looks better than a chunky profile that fights the design.

FAQ

What size round-over bit should I use?

Use 1/8 in to 1/4 in for most shelves, boxes, and cabinet parts. Use 3/8 in to 1/2 in on thicker tops where you want a softer feel. Always leave enough flat on the face so the bearing has a clean reference and the remaining edge does not become fragile.

Should I round over before or after assembly?

Round over individual parts when you can reach every edge safely. After assembly works for exposed outer edges, but inside corners need a different approach or hand work. Dry-fit first so hardware and joinery clearances stay correct.

Why is my round-over leaving burn marks?

Common causes are a dull bit, too-slow feed, pitch buildup, or RPM that is too high for the bit diameter. Clean the cutters, increase feed slightly, drop speed on large bits, and confirm the bearing is not dragging and scorching the face.

Can I round over plywood edges?

Yes, with a sharp bit and controlled feed. Plywood veneer chips easily, so take lighter passes and support the exit edge. A smaller radius often looks cleaner on plywood than a large profile that exposes more core layers.

Do I need a bearing-guided round-over bit?

A bearing makes consistent edge work much easier because it follows the face automatically. Without a bearing you need a fence or edge guide and careful setup. For most furniture and cabinet edges, a bearing-guided bit is the practical choice.

How do I round over both faces for a bullnose?

Cut one face fully, flip the board, and match the second radius so the two arcs meet. Use the same bit height and scrap tests for both sides. On thick stock, verify the meeting line is centered before finish sanding.

Is a palm router enough for round-overs?

A quality palm or trim router handles small radii well on light stock. Larger diameters and thick hardwoods are more comfortable in a mid-size router with better mass and speed control. Match tool size to bit diameter and material hardness.