Materials
CNC Dibond & ACM Cutting
Aluminum composite material—the sign industry staple. Fast, clean cuts for flat panel signs, dimensional letters, and architectural applications.
Aluminum Composite on CNC
ACM (Aluminum Composite Material) is two thin aluminum sheets bonded to a polyethylene core. Light, rigid, flat, and weather-resistant—it’s become the standard for exterior signage and architectural panels.
Dibond is the best-known brand, but Alupanel, Reynobond, and others are similar materials. They all cut the same way on a CNC router.
Despite having aluminum faces, ACM machines more like plastic than metal. The core is soft polyethylene; the aluminum skins are thin. Proper tooling cuts through cleanly at high speed.
ACM Material Characteristics
Construction
Two aluminum skins (typically 0.012″-0.020″ each) bonded to polyethylene core (typically 3mm total thickness).
Weight
Lightweight despite rigidity. Fraction of solid aluminum weight. Easy to handle and install.
Flatness
Manufactured flat and stays flat. Ideal for panel signs where appearance matters.
Finishes
Painted, anodized, brushed, and specialty finishes. Wide color range for sign applications.
Weather Resistance
Exterior rated for long-term outdoor use. Aluminum faces don’t rust or degrade.
Sizes
Standard 4×8 and 5×10 sheets. Custom sizes available. Nests efficiently on CNC tables.
Tooling for ACM
Single Flute / O-Flute
Large chip clearance works well for ACM. Single cutting edge, high helix, polished flute. Clears the soft core material efficiently.
Chip Breaker Geometry
Some ACM-specific bits include chip breaker features. Produces smaller chips that eject more easily and don’t string.
Two-Flute Options
Work fine with proper chip load. Better finish potential on the aluminum faces.
Standard Carbide
ACM doesn’t wear tools quickly. The aluminum is thin and the core is soft. Quality carbide lasts well.
Diameter Selection
1/8″ to 1/4″ most common. Match to your detail requirements. Smaller for letters, larger for faster profiling.
ACM Cutting Parameters
ACM cuts fast. Single-pass profiling is standard. Keep feeds and speeds balanced for clean edges.
ACM Applications
Flat Panel Signs
The classic ACM application. Route to shape, add graphics. Clean, professional exterior signs.
Dimensional Letters
Cut letters from ACM panels. Lightweight, weather-resistant, paintable.
Architectural Panels
Building cladding, interior panels, decorative elements. ACM’s flatness suits architectural applications.
Trade Show Displays
Lightweight, rigid panels for portable displays. Easy to transport and assemble.
Wayfinding
Directional signs, maps, information panels. Durable for public installations.
Backer Panels
Backing for channel letters and other sign types. Strong, flat substrate.
ACM Cutting Technique
Single Pass Cutting
At 3mm or 4mm thick, ACM profiles in a single pass. No need for depth stepping. Fast cycle times.
Vacuum Hold-Down
ACM seals well on vacuum tables. The aluminum faces are non-porous. Standard vacuum setup works fine.
Edge Quality
Proper tooling and parameters produce clean edges. The aluminum skin cuts smoothly; the core doesn’t fuzz like wood.
Protect the Finish
Leave protective film on during cutting. Remove after machining to reveal clean, unscratched surface.
Routing for Folding
ACM can be V-grooved and folded for dimensional fabrication. Route channels that allow bending without cracking.
Ready for ACM Production?
CNC makes Dibond and ACM fabrication fast and efficient.