Industrial CNC & Laser Insights

Download the definitive CNC router speeds and feeds chart for plywood, hardwood, MDF, acrylic, foam, and stone. Optimize RPM, feed rate, depth of cut, and tooling selection for flawless non-metal machining.

Ⅰ. Introduction: Why Non-Metal Materials Demand Their Own Parameter Library

A CNC router that cuts plywood at 15 meters per minute cannot cut acrylic at the same speed without melting the edge. A feed rate that produces a clean finish in solid maple will tear out the surface grain of red oak. Non-metal materials—wood, plastic, foam, composite, and stone—respond to the cutting tool in fundamentally different ways because their internal structures differ at the microscopic level. Wood is fibrous and anisotropic. Acrylic is a thermoplastic that softens before it shears. Foam is a low-density cellular solid that collapses under too much tool pressure.

This guide is the parameter library that accounts for those differences. It compiles spindle RPM, feed rate, depth of cut, step-over, and tooling recommendations for every non-metal material category processed on industrial CNC routers. The values are drawn from the documented cutting databases of leading machine tool manufacturers and validated against the mechanical properties of each material as published in ISO and ASTM standards. Whether you operate a flatbed woodworking router, a 5-axis foam carver, or a stone engraving gantry, the tables that follow provide production-ready starting points. For shops managing diverse material inventories on YIHAICNC’s integrated CNC router and laser fabrication platforms, this parameter reference enables rapid job changeover without trial-and-error scrap.

Ⅱ. The Chip Formation Mechanism: How Non-Metal Materials Separate Under the Tool

To understand why a parameter works, the operator must understand how the material fails. Wood, plastic, foam, and stone each fail by a different mechanism, and that mechanism determines the allowable chip load, the optimal tool geometry, and the resulting surface finish.

1. Wood: Fracture Along the Grain

Wood is a natural composite of cellulose fibers bound by lignin. When a rotating cutter edge impacts a wood cell wall, the wall fractures along the grain direction, not along the cutter path. This anisotropy explains why climb cutting (where the cutter rotation direction matches the feed direction) produces a cleaner edge on wood than conventional cutting: in climb cutting, the chip thickness starts at maximum and decreases, compressing the wood fibers before shearing them. In conventional cutting, the chip starts at zero thickness, rubs, then wedges under the fiber, lifting and tearing it.

According to fundamental wood machining research published in Wood Science and Technology, the critical chip thickness for clean cutting of hardwood is approximately 0.05 mm. Below this threshold, the tool rubs rather than cuts, generating friction heat that burns the wood surface. The parameter tables in this guide maintain chip loads above this minimum for every wood type.

2. Acrylic and Thermoplastics: Shear and Softening

Acrylic (PMMA) and other thermoplastics do not fracture; they shear. The polymer chains must be cleanly severed by a sharp cutting edge. If the tool is dull or the feed rate too high, the acrylic heats above its glass transition temperature of approximately 105°C and begins to soften. The softened material smears onto the tool rather than being ejected as a chip. The result is a melted, opaque edge that requires extensive post-processing. The cutting parameters for acrylic in this guide maintain chip loads and surface speeds that keep the cutting zone below the softening temperature.

3. Foam: Cell Collapse and Elastic Recovery

Polyurethane and polystyrene foams are cellular solids. When a cutter moves through foam, it must sever the cell walls cleanly. A dull tool or an excessive feed rate crushes the cells ahead of the cutting edge, causing permanent deformation that leaves a rough, torn surface. The optimal tool for foam is a high-speed steel or carbide cutter with an extremely sharp edge and a high positive rake angle. Chip evacuation is critical—foam chips are voluminous and must be removed rapidly to prevent re-cutting.

4. Stone and Solid Surface: Brittle Fracture and Abrasive Wear

Granite, marble, and engineered stone do not shear; they fracture through brittle crack propagation. The cutting tool does not slice the stone but induces microcracks ahead of the cutting edge that coalesce into a chip. This process generates extreme abrasive wear on the tool. Only diamond-grit tooling survives more than a few linear meters of stone cutting. Coolant—typically water—is mandatory to suppress dust and to carry heat away from the diamond cutting surface.

The table below summarizes the failure mechanism for each material class and the resulting parameter constraints.

Ⅲ. Wood Products Parameter Charts

Wood products are the foundation of CNC router work. The parameter tables below cover the complete range of wood-based materials processed in furniture, cabinetry, sign making, and architectural millwork. All values assume carbide tooling with sharp cutting edges, a rigid gantry machine, and effective dust extraction.

1. Solid Hardwood Parameters

Solid hardwood varies in density from approximately 400 kg/m³ (basswood) to over 1,000 kg/m³ (lignum vitae), with corresponding variation in cutting force and optimal feed rate. According to ISO 3129 wood sampling standards, mechanical properties including density, modulus of rupture, and Janka hardness directly determine allowable chip load and cutting speed. The table below provides settings for the hardwoods most commonly processed on CNC routers.

For 3D carving with ball nose tools, the step-over percentage directly controls surface finish. A 10% step-over with a 6.35 mm ball nose produces a finish that requires minimal sanding; a 5% step-over may eliminate sanding entirely at the cost of significantly longer machining time. The relationship between step-over and cusp height is geometric: cusp height = step-over² / (8 × tool radius). Wikipedia’s entry on CNC router woodworking provides additional context on toolpath strategy for 3D wood carving.

2. Softwood Parameters

Softwoods present two challenges: wide density variation between earlywood and latewood bands, and resin content that gums cutting edges. Tooling must remain sharp; a dull tool compresses the soft earlywood rather than cutting it, producing a fuzzy surface.

3. Engineered Wood Products: Plywood, MDF, and OSB

Engineered panels present different challenges than solid wood. Glue lines in plywood are abrasive and can delaminate under excessive feed force. MDF produces fine, choking dust that demands high-volume extraction. OSB has random strand orientation that causes unpredictable tearout.

4. Wood Engraving and V-Carving Parameters

V-carving produces dimensional lettering and decorative details by varying the depth of a V-shaped cutter. The width of the cut is determined by how deep the V-bit plunges. The parameters below apply to V-carving on wood substrates.

Ⅳ. Acrylic and Thermoplastic Parameters

Acrylic, polycarbonate, HDPE, and other thermoplastics machine well on CNC routers provided the cutting zone temperature remains below the material’s softening point. Cast acrylic is preferred over extruded for machining because its higher molecular weight produces a cleaner chip that does not gum the tool.

1. Acrylic (Cast and Extruded) Cutting Parameters

Cast acrylic machines with a characteristic sweet smell; the chips are distinct granules. If the edge appears melted, white, or gummy, reduce spindle RPM or increase feed rate to move heat into the chip rather than the workpiece. For shops that process both wood and acrylic on the same machine, YIHAICNC’s technical blog and knowledge base offers guidance on spoilboard management to prevent cross-contamination between wood dust and acrylic chips.

2. Polycarbonate, HDPE, and PVC Parameters

A critical note on PVC: while PVC foam board machines easily, thermal decomposition of PVC releases hydrogen chloride gas. Dust extraction must be functional, and operators should never laser-cut PVC. CNC routing is the safe processing method for this material. OSHA workplace exposure limits for HCl are 5 ppm as a ceiling concentration; standard workshop ventilation is typically adequate for routing operations but must be verified.

Ⅴ. Foam, Solid Surface, and Stone Parameters

These three material classes represent the extremes of the density spectrum—from 30 kg/m³ expanded polystyrene to 2,800 kg/m³ granite. Each demands fundamentally different tooling and strategy.

1. Foam Parameters (PU, PS, PE)

Foam routing is characterized by very high feed rates, deep single-pass cuts, and specialized tooling with extreme positive rake angles. Standard carbide end mills will cut foam, but foam-specific tools with polished flutes and large chip clearances produce far superior surface finishes. According to data from leading CNC machine tool builders, foam can be routed at feed rates exceeding 15 m/min with the correct tooling and machine acceleration.

2. 3D Foam Carving: Roughing and Finishing Parameters

For 3D foam carving—architectural models, thermoforming molds, signage, and sculptural work—a two-stage strategy of roughing followed by finishing provides the optimal balance of speed and surface quality.

The finishing step-over percentage is the dominant variable controlling surface smoothness. A 10% step-over with a 6.35 mm ball nose leaves cusps approximately 0.04 mm high—barely perceptible to touch. Reducing step-over to 5% with a 3.175 mm ball nose produces a surface ready for primer without sanding. For facilities operating 5-axis foam carvers, YIHAICNC’s comprehensive CNC router product range includes multi-axis configurations that enable undercut carving and complex geometry machining without repositioning the workpiece.

3. Solid Surface Parameters (Corian, Hi-Macs, Staron)

Solid surface materials—composed of acrylic or polyester resin filled with alumina trihydrate—machine similarly to cast acrylic but are significantly more abrasive due to the mineral filler. Tooling must be carbide, and cutting edges dull faster than when machining unfilled acrylic.

4. Stone Engraving and Machining Parameters

Stone is processed on CNC routers equipped with diamond tooling and water cooling. The router’s gantry and Z-axis must be sealed against abrasive stone slurry. Spindle speed is lower than for wood or plastic to prevent diamond tool degradation from excessive heat.

For shops that process stone alongside wood and plastics, machine maintenance is critical. Stone slurry is abrasive and will destroy linear rails and ball screws if not contained. Dedicated stone machines with sealed motion components, or rigorous cleaning protocols for multi-material machines, are essential. YIHAICNC’s after-sales service and technical support team provides guidance on machine configuration and maintenance scheduling for shops processing abrasive materials.

Ⅵ. Tooling Geometry Selection: The Foundation of Every Parameter

The parameter tables above all assume specific tool geometries. A parameter that works with a single-flute O-flute cutter will produce a completely different result with a two-flute straight cutter. The relationship between tool geometry and material is governed by the rake angle, clearance angle, helix angle, and number of flutes.

1. Tool Geometry Recommendations by Material Class

2. Tool Diameter and Rigidity Considerations

Tool deflection is proportional to the cube of the tool’s length-to-diameter ratio. For finishing operations where surface finish is critical, the tool should be as short as practical and as large in diameter as the geometry permits. A 6 mm diameter tool protruding 30 mm from the collet deflects approximately eight times more than the same tool protruding 15 mm. The depth of cut must be reduced when long-reach tooling is unavoidable.

Ⅶ. Motion Dynamics and Machine Capability: Translating Parameters to Production

The speed and feed values in the parameter tables can only be achieved if the CNC router’s motion system can accelerate to the programmed feed rate within the available cutting distance. On parts with short segments and frequent direction changes, the machine may never reach the target feed rate. Understanding the relationship between acceleration, corner geometry, and actual cutting speed is essential for accurate cycle time estimation and tool life prediction.

1. Acceleration and Its Impact on Effective Feed Rate

A machine with an acceleration of 1,500 mm/s² requires approximately 0.2 seconds and 45 mm of travel to accelerate from rest to 4,000 mm/min. On a part with 50 mm linear segments, the machine spends nearly half the cut at less than the programmed speed. This has two consequences: the actual cycle time is longer than the distance divided by feed rate would predict, and the tool experiences varying chip loads during acceleration and deceleration.

According to Autodesk’s CAM documentation on high-speed machining, adaptive clearing toolpaths maintain a constant tool engagement angle by varying the toolpath radius rather than the feed rate. This constant engagement produces consistent chip loads and extends tool life, particularly in metals but also in abrasive wood species. For complex non-metal parts with numerous short segments, enabling high-speed machining look-ahead and corner smoothing in the CNC controller significantly improves both cycle time and surface finish.

2. Climb Milling vs. Conventional Milling for Non-Metals

Climb milling is the standard for non-metal machining. The cutter enters the material at maximum chip thickness and exits at zero, compressing the material before shearing it. This compression prevents the lifting and tearing that occurs in conventional milling, particularly at the edges of plywood and along the grain of hardwood. The exception is stone, where conventional milling can reduce edge chipping by directing the cutting force into the material rather than outward.

3. Vacuum Hold-Down Effectiveness by Material Type

Vacuum hold-down, the standard workholding method for flatbed routers, varies in effectiveness by material porosity and weight.

For machines lacking sufficient vacuum for small non-porous parts, onion-skinning—leaving a 0.2–0.5 mm skin of material at the bottom of the cut, then releasing the part with a manual trim—is a reliable strategy. The skin holds the part in place during machining and is easily removed with a knife or a light sanding pass. For shops seeking vacuum system upgrades, YIHAICNC’s contact page connects to application engineers who can specify pump capacity based on material mix and table size.

Ⅷ. FAQ

1. How do I calculate the feed rate for a material not listed in this guide?

Start by determining the recommended chip load for the material and tool combination. For wood, a chip load of 0.1–0.25 mm per tooth is typical for tools 6 mm and larger. For acrylic, 0.05–0.15 mm per tooth. Apply the formula: Feed Rate (mm/min) = Spindle RPM × Number of Flutes × Chip Load. Set the spindle RPM based on the recommended surface speed (SFM) for the material. For hardwoods, SFM is 500–1,500 m/min with carbide tooling; for acrylic, 200–600 m/min. Convert SFM to RPM using: RPM = (SFM × 1000) / (π × Tool Diameter in mm). Begin with a reduced depth of cut and increase until surface finish or machine rigidity limits are reached.

2. Why does my router bit burn wood even at the recommended parameters?

Burning indicates that the tool is rubbing rather than cutting. This happens when the chip load is too low—the cutting edge skates over the surface, generating friction heat instead of forming a chip. The most common causes are spindle RPM set too high relative to the feed rate, or a dull tool that no longer has a sharp cutting edge. Verify that your actual chip load exceeds 0.05 mm per tooth. If it does and burning persists, the tool is dull and must be replaced. Using a climb milling toolpath direction also reduces burning by minimizing the distance the tool rubs before engaging the material.

3. Can I use the same compression bit for plywood and melamine-faced chipboard?

Yes, a carbide compression bit designed for laminated panels works well on both materials. The compression geometry—up-cut at the tip transitioning to down-cut at the shank—presses the top and bottom veneers or laminates toward the core, preventing chipping on both faces. The key is to set the depth of cut so that the transition point between up-cut and down-cut flutes is fully within the material thickness. If the transition point is above or below the material, one face will experience the wrong shear direction and chip.

4. What is the best way to prevent acrylic from melting during CNC routing?

Acrylic melting is caused by heat buildup at the cutting zone. Three adjustments prevent it: reduce spindle RPM to lower the surface speed, increase feed rate to move heat into the chip rather than the workpiece, and use a single-flute O-flute cutter that provides maximum chip clearance and prevents chip re-welding. Compressed air directed at the cut zone provides additional cooling. If melting persists, verify that the tool is sharp—a dull tool generates significantly more heat than a sharp one. The acrylic chips should be distinct granules, not melted globs.

5. How do I achieve a paint-ready edge on MDF without sanding?

Use a sharp carbide compression bit, set the correct RPM and feed rate to produce a clean shear cut, and take a finishing pass at 0.2–0.5 mm depth of cut after the main profile cut. The finishing pass removes the small amount of material that may have been compressed or roughened by the primary cut. A 2-flute straight bit with a climb milling toolpath direction produces the smoothest MDF edge. The edge can then be sealed with a sanding sealer or primer without mechanical sanding.

6. What safety precautions are required when routing foam?

Polyurethane and polystyrene foam dust is combustible. The dust collection system must be grounded to prevent static electricity discharge, and the collected dust must be removed from the workshop regularly. PVC foam board thermal decomposition releases hydrogen chloride gas if overheated; maintain correct cutting parameters to prevent excessive tool temperature. Polyisocyanurate foam contains isocyanate compounds that are respiratory irritants; dust extraction and operator respirators are recommended. Always consult the material safety data sheet for the specific foam product before machining.

7. How often should I resurface my spoilboard?

Resurface the spoilboard whenever visible grooves, steps, or uneven wear appear, or when the vacuum hold-down effectiveness noticeably decreases. In a production shop processing MDF and plywood daily, resurfacing every one to two weeks is typical. The spoilboard should be surfaced flat within 0.05 mm across the entire table using a large-diameter fly cutter or surfacing bit. A flat spoilboard is the foundation of dimensional accuracy; depth errors in the spoilboard transfer directly to the workpiece. When the spoilboard thickness drops below approximately 10 mm, it should be replaced.

Ⅸ. Conclusion

This cnc router speeds and feeds chart provides the parameter foundation for machining the complete spectrum of non-metal materials on industrial gantry routers. From soft cedar to hard maple, from cast acrylic to abrasive solid surface, from lightweight foam to dense granite—each material class responds to the cutting tool according to its internal structure. The parameters in the tables deliver chip loads that keep the tool cutting rather than rubbing, surface speeds that prevent thermal damage, and depths of cut that respect the machine’s rigidity.

The single principle that unifies all the tables is chip load. Maintain the recommended chip load, and the material cuts as intended. Allow the chip load to drop below the minimum threshold, and the tool rubs, heats, and degrades. The other variables—spindle RPM, feed rate, depth of cut, step-over, coolant—all serve to produce the correct chip load in the specific material and tool combination. Validate these starting parameters on your machine, fine-tune them by the diagnostic procedures in Section Ⅶ, and document the results. A shop’s own validated parameter library, calibrated to its specific machines and material suppliers, is the most valuable productivity asset it can build.

Further Reading on CNC and Laser Parameters:

• CO2 Laser Speed and Power Chart for Non‑Metal Materials — When a laser offers faster, cleaner cuts on acrylic, wood, and leather.
• CNC Router Metal Cutting – Speed & Feed Chart — Expand your router’s capability to aluminum, brass, and copper.
• Fiber Laser Metal Cutting – Speed & Power Settings — For shops considering a dedicated metal cutting laser.