A metal router plane is used for precise leveling and planning of grooves, rebates, and slots down to the bottom. It is employed whenever the depth of a recess needs to be created or reworked with precision and repeatability—such as when adjusting tenon and mortise joints, smoothing rebate bottoms, working on hidden grooves, inlays, or for flush removal of glue residue or small elevations within a recess.

Design and Handling

- The metal body (often made of torsion-resistant cast) provides a flat, long sole for good guidance and dimensional accuracy.

- A centrally positioned, height-adjustable blade operates directly in front of the sole; the cutting depth can be finely adjusted and securely fixed.

- Side knobs or wing handles allow for controlled feed and define the pressure applied.

- Depending on the model, open or closed mouth designs are available. Open designs offer visibility of the blade, while closed ones support the sole on narrow edges.

- Accessories such as parallel guides (for work along an edge), depth stops (for reproducible depth), or enlarging auxiliary soles (e.g., wood or plastic soles) expand the range of use, especially with narrow workpieces or wide grooves.

Blade Types and Sharpening

- Available are straight blades in various widths as well as tapered or spear-point blades for reaching corners.

- A clean, polished grind with an effective cutting angle of approximately 25–30° and finely honed bevels ensures smooth cutting and even bottoms.

- For sensitive woods, a fine honing is recommended; with tough material, a micro-bevel can increase edge retention.

Operation and Practical Tips

- Securely clamp the workpiece; lay out lines clearly with a marking gauge or knife.

- For tear-free edges, initially work close to the layout line (e.g., with a chisel), then plane the bottom to final depth with the router plane.

- Set the depth in small increments; prefer multiple light passes over one aggressive cut.

- For long grooves, work from both ends toward the center to avoid tear-out at the exit edge.

- Auxiliary soles increase the support surface and enhance control on narrow bridges.

Sizes and Areas of Application

- Compact models are suitable for narrow grooves, inlays, and detailed work.

- Medium-sized versions cover general furniture and interior construction.

- Large router planes offer maximum support and are advantageous for leveling wide rebate bottoms or long grooves.

Advantages of Metal Construction

- High shape stability and flatness of the sole for reproducible results.

- Precise depth micro-adjustment and secure locking.

- Good compatibility with fences, auxiliary soles, and different blade types.

Care and Maintenance

- Lightly deburr and wax the sole as needed; this reduces friction.

- Protect metal surfaces from corrosion (e.g., with a thin oil film or wax).

- Regularly sharpen and hone blades; clean edges minimize chatter marks and improve surface quality.

With this equipment and operation, a metal router plane delivers flat, dimensionally accurate bottoms in grooves and recesses and complements planes, routers, and chisels as a precise tool for the final fit.