Comprehensive CNC Router Bits Glossary – Part 1

Welcome to the first part of our expert CNC router bits glossary. Below you’ll find clear, authoritative definitions for a wide range of bit types, tools, and key machining terms.

A

Abrasive Router Bits: Designed specifically to carve or engrave abrasive materials—including tile, fiberglass, wood, and diamond composites.

Acrylic CNC Router Bits: Optimized for cutting acrylic. Acrylic’s softer nature can quickly dull steel bits, so specialized bits are recommended.

Aluminum Router Bits: Ideal for cutting non‑ferrous metals such as aluminum, brass, and copper.

Angles: Measures of divergence between two lines. Includes cutting angles, included angles, clearance angle, end‑clearance angle, and tip angle.

Axial Load: Force applied along the axis of a tool; typically expressed as a percentage of the tool’s diameter.

Axis: The central line—real or imaginary—around which a component rotates. A, C, X, Y, and Z reference points are common on CNC machines.

Architectural Bits: High‑quality wood‑cutting tools with a mirror‑finish carbide edge for fine, precise cuts.

B

Backlash: Play or lost motion in moving parts that can affect dimensional accuracy.

Binder: Metallic component in carbide that holds the grains together.

Brazing: Joining metals by heating a non‑ferrous alloy with a flux to its lower melting point.

Burning: When excessive speed or feed causes wood surfaces to discolor or smoke, indicating overheating.

Bevel: A sloping edge that gives a bordering effect, often seen on nameplates.

Ball‑Nose Bits: Used for carving decorative doors and signs; provide a smooth finish and efficient chip removal.

Beadboard CNC Bits: Computerized shaping tools that create bead or flute patterns for lettering and trimming.

Beading Router Bits: Engrave quarter‑round shapes bordered by fillets, commonly used in tongue‑and‑groove joints.

Ball End Router Bits: Small rounded profile bits for cutting channels for pipes or cables.

Boring Bits Lance: Pointed‑tip bits designed for piercing or drilling hard wood.

Bowl & Tray Router Bits: Route solid wood trays or flat dishes.

Bullnose Router Bits: Carve rounded edges, often used for countertop fronts.

Bench Dog: Metal or wooden peg that secures a workpiece on a workbench; fits into a spring‑loaded hole.

From Wood Magazine

C

CNC Router: A computer‑controlled cutting machine that works with wood, composites, aluminum, steel, plastics, and foams.

Carbide Tipped Tools (CT): Constructed from tungsten, tantalum, and cobalt for extreme hardness and abrasion resistance.

Center‑Less Grinding: Grinding process where the tool is supported by a blade rest and balanced by a regulating wheel.

From Slideshare – Grinding Operation

Chamfer Router Bits: Engrave angled edges on material surfaces.

Compression Router Bits: Ideal for veneer and melamine; drill both top and bottom edges toward the center.

Core Box Router Bits: Engrave half‑round grooves for fluted moldings and columns.

Corner Round Router Bits: Produce rounded corners on furniture and cabinetry.

Countersink: Creates a hole that allows a screw head to sit flush with the surface.

Cove Router Bits: Carve detailing in cove trim, doors, drawers, posts, and columns.

Crown Molding: Trim that conceals the joint between walls and ceilings.

Comparator: Measures optical images for precise geometry comparisons.

Collet: Collar that clamps a tool or part with a tapered outer collar.

Custom Router Bits: Custom‑made bits tailored to specific customer requirements.

Clearance Angle: Angle between the clearance surface and a plane tangent to the cutting edge.

D

Door Lip Router Bits: Shape handles on drawer fronts and cabinet doors.

Door Making Router Bits: Shape and compose doors.

Double Bead Router Bits: Create two bead‑shaped contours; useful on shelving edges.

Deflection: Uneven contact of the workpiece with the grinding wheel or milling cutter, often due to high feed rates.

Degree and Minutes: Unit of angular rotation: 360° per circle, 60 minutes per degree.

Dovetail Joints: Interlocking wood joints used for drawers and cabinets.

Dovetail Router Bits: Carve tenons and mortises for dovetail joints.

Dowel: Cylindrical wooden pin used to reinforce joints.

Dowel Center: Metal pin with raised points that centers dowel holes.

Downcut: Helix that moves opposite the tool rotation, forcing chips downward.

DACS (Digitally Aligned Cutting System): Provides precise print‑to‑cut registration for CNC routing machines.

Diamond Engraving: Uses a non‑rotating diamond‑tipped graver to etch fine lines into metal.

E

End Mill High‑Performance Fiberglass and Composite Cutting Router Bits: Combines a flute end mill with a diamond‑cut tip for superior finish on composites.

Engraving Bits: Carve specific designs into wood, plastic, and metal surfaces.

E‑Z Dial Slot Cutter Router Bits: Adjustable slot cutter that tunes in seconds and offers ±0.004″ precision.

Edge Joining: Smooths and squares board edges to create tight joints.

F

Face: Axial cutting length of an engraving tool.

Flute Face: Flat portion of the flute adjacent to the web and ending at the cutting edge.

Fade Out: Section of the flute that retracts from the workpiece, located between the Cel and Shank.

Feed Rate: Speed of rotation (RPM) and linear movement (IPM) that determines safe and efficient machining.

Feed Elevation: Vertical feed adjustment on a grinder column that raises or lowers the grinding head.

Feed Index: Cross‑index measurement related to workpiece diameter or radius.

Feather Board: Wood piece that holds a board against a router fence or table.

From Popular Woodworking – Walnut Entertainment Center

Fence: Straight guide that controls distance from the blade to the workpiece.

Flat‑Sawn Lumber: Also called plain‑sawn; lumber cut peripherally to growth rings.

Flooring Router Bits: Cut slots into wood flooring, medallions, and inlays.

Flush Trim Router Bits: Create an edge that is flush with another material.

Fluted Moldings/Fluting: Curved channels that form decorative patterns along a molding’s length.

From Infinity Tools – Triple Bead & Flute Router Bit Set

To be Continued – CNC Router Bits Glossary 2