R4 Rounding Cutter with Guide Bearing

The RUWI R4 Rounding Cutter 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 stop fits.

The router bit is double-edged and carbide-tipped (HW, Z2), right-hand rotation, with a diameter of 21 mm tool diameter and 10 mm working length; shank , 8 mm diameter, overall length , 56 mm. It cuts softwood, hardwood, and laminated 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