Roundover bit R4 with guide bearing

The RUWI roundover bit R4 rounds off wood edges with a 4-mm radius—a subtle, even curve that softens the edge without standing out as a distinct profile. The lead-in ball bearing (Ø 12.7 mm) runs along the workpiece edge and guides the cutter even along curved contours for which no fence fits.

The router bit is double-edged and carbide-tipped (HW, Z2), right-hand rotation, with a Ø 21 mm tool diameter and 10 mm working length; shank Ø 8 mm, overall length 56 mm. It cuts softwood, hardwood, and coated panels. If the ball bearing wears out, you can replace it—instead of replacing the entire router bit.

Here's how to use it

• Subtly soften visible edges: The 4-radius takes the sharpness out of furniture fronts and trim—from a distance, the edge appears straight, but when held in the hand, it feels rounded.
• Children's and everyday furniture: rounded edges where people touch and bump into them every day.
• Freehand operation on the router: the compact Ø-21 head runs smoothly when guided by hand—for edges on assembled furniture and on the job site.
• Batch processing on the table: On the router table, you guide the workpiece past the stationary milling cutter—edge by edge, with the same profile.

Does this fit your router?

The shank requires an collet Ø 8 mm – at RUWI router table Standard; it is also compatible with hand-held routers, bench routers, and CNC machines. The compatible tables are shown in the RUWI router tables.

Heavy-duty, round R5 to R12.7, fine R3 and R2—the entire range provides an overview of RUWI 's milling tools.

All the details

Profile
Radius: 4 mm
tool diameter : Ø 21 mm
working length : 10 mm
overall length : 56 mm

shank and thrust bearing
shank : Ø 8 mm, shaft length 32 mm
Thrust bearing: Ball bearing Ø 12.7 mm, replaceable

Cutting edges and insert
Cutting edges: Z2, carbide (HW), clockwise rotation
Materials: Softwood, hardwood, coated panels
collet : Ø 8 mm required
net weight : approx. 31 g