L'usinage CNC fonctionne avec deux grandes familles de matériaux: métaux et plastiques. Votre choix de matériau définit la solidité, poids, résistance à la corrosion, usinabilité, état de surface, et le coût. The right choice always depends on the part’s loads, environnement, and tolerances—never on a single property. This guide covers the common metals and plastics, how to choose, and when each one earns its cost.
How To Choose A CNC Machining Material
Start by evaluating these five key factors:
- Service conditions.Confirm temperature, produits chimiques, humidité, UV, and food or medical contact.
- Propriétés mécaniques.Define required strength, dureté, rigidité, et résistance à l'impact.
- Usinabilité.Estimate how fast and cleanly the material cuts.
- Finition de surface.Decide on as-machined roughness, anodisation, placage, ou revêtement.
- Coût.Compare raw material price, temps de cycle, et l'usure des outils.
Material Grade And Condition Matter
The alloy name alone is not always enough when you specify a CNC machining material. Caractère, traitement thermique, dureté, and material condition can significantly affect strength, usinabilité, stabilité dimensionnelle, et le coût.
- Aluminium 6061 is not the same as 6061-T6. The “-T6” temper means the material was solution heat-treated and artificially aged, which changes both strength and machinability.
- Acier inoxydable 17-4 PH is not a generic stainless. Its strength and hardness change with the aging condition, such as H900 versus H1150.
- 4140 steel changes with heat treatment. Recuit 4140 machines easily. Endurci 4140 is stronger but slower and more expensive to cut.
Specify the full grade, caractère, and condition on your drawing. That one line removes ambiguity in quoting, usinage, et inspection, and it lets the shop match the correct material certificate.
CNC Machining Metals
Metals dominate CNC work because they deliver strength, tolérances étroites, and repeatable finishes.
| Matériel | Notes communes | Key Advantages | Applications typiques |
| Aluminium | 6061-T6, 7075-T6 | Poids léger, usinable, résistant à la corrosion | Aérospatial, électronique, automobile |
| Acier | 1018, 4140, 4340, acier à outils | Haute résistance, hardenable, difficile | Arbres, outillage, pièces structurelles |
| Acier inoxydable | 303, 304, 316, 17-4 PH | Résistant à la corrosion, hygiénique, fort | Médical, nourriture, marin |
| Titane | Grade 5 (Ti-6Al-4V) | Excellent rapport résistance/poids, biocompatible | Aérospatial, médical |
| Cuivre | C110 | Excellente conductivité | Composants électriques |
| Laiton | C360 | Free-machining, conducteur | Raccords, connecteurs |
| Bronze | C932 | Résistant à l'usure, faible frottement | Bagues, roulements |
| Magnésium | AZ31B | Very low density and excellent strength-to-weight potential | Lightweight housings |
| Zinc | les fardeaux 3 | Faible coût, dimensionnellement stable | Petites pièces |
| Fonte | Gris, ductile | Vibration damping, résistant à l'usure | Bases de machines, outillage |
6061-T6 en aluminium is one of the most widely used CNC machining materials for general-purpose structural and mechanical parts. Utiliser 7075 aluminium when you need higher strength. Choisir 304 ou 316 acier inoxydable for corrosion and hygiene. Choisir titane when its strength-to-weight ratio, résistance à la corrosion, biocompatibilité, or temperature performance justifies the higher material and machining cost. Acier allié et acier à outils suit high-strength and wear applications.
Usinage CNC des plastiques
Plastics are chosen for light weight, isolation électrique, résistance chimique, or lower cost.
| Plastique | Why Engineers Choose It |
| abdos | Difficile, faible coût, facile à usiner |
| Acrylique (PMMA) | Clair, rigide, polishes well |
| Nylon (Pennsylvanie) | Fort, résistant à l'usure |
| Delrin / Acétal (POM) | Rigide, faible frottement, excellente machinabilité |
| COUP D'OEIL | Haute résistance et résistance à la chaleur |
| PTFE | Faible frottement, résistance chimique, suitable for many food-contact applications |
| Polycarbonate (PC) | Difficile, transparent, Résistant aux impacts |
| PEHD / UHMW-PE | Faible frottement, résistant aux produits chimiques |
| PPS | High heat and chemical resistance |
| Ultem (Î.-P.-É.) | Flame-resistant, haute résistance |
| Torlon (PAI) | Very high strength at temperature |
Delrin et nylon cover most general-purpose plastic parts. Utiliser COUP D'OEIL ou Ultem for high-temperature or medical work. PTFE et PEHD suit chemical and food-contact service. Acrylique gives you transparent, polished parts.
Quick CNC Material Selection Guide
| If you need… | Consider… |
| Low cost and easy machining | 6061 aluminium, laiton, Delrin |
| Rapport résistance/poids élevé | 7075 aluminium, titane |
| Résistance à la corrosion | 316 acier inoxydable, titane |
| Conductivité électrique | Cuivre, laiton, aluminium |
| Résistance à haute température | COUP D'OEIL, Î.-P.-É., PPS |
| Faible frottement | POM, PTFE, UHMW-PE |
| Résistance à l'usure | Acier à outils, POM, UHMW-PE |
| Transparence | Acrylique, polycarbonate |
| Medical applications | 316L stainless steel, titane, COUP D'OEIL |
CNC Machining Materials By Application
| Application | Material To Consider | Pourquoi |
| Aérospatial | 7075 aluminium, titane, COUP D'OEIL, Ultem | Strength-to-weight and heat resistance |
| Médical | 316L stainless, titane, COUP D'OEIL | Biocompatibility and cleanability |
| Food Contact | 304/316 inoxydable, Delrin, PTFE, PEHD | Nettoyable, non-toxic surfaces |
| Électrique | Cuivre, laiton, aluminium | Conductivité |
| Température élevée | Titane, acier à outils, COUP D'OEIL, Torlon | Résistance à la chaleur |
| Chemical Service | 316 inoxydable, PTFE, PEHD, PPS | Résistance chimique |
| Prototypage | 6061 aluminium, abdos, Delrin | Fast and low cost |
| Wear Parts | Hardened tool steel, Delrin, UHMW-PE | Résistance à l'usure |
Machinability And Surface Finish
Machinability describes how easily a material cuts. It drives cycle time, usure des outils, finition, et le coût.
- Free-machining materials.Brass C360, 303 inoxydable, 6061 aluminium, and Delrin cut fast and finish well.
- Difficult materials.Titane, acier durci, and superalloys need slow feeds and more tool wear.
- Metal finishes.Aluminum can be anodized; stainless can be passivated or electropolished; steel can be plated.
- Plastic finishes.Plastics usually need polishing or vapor polishing to remove tool marks.
Learn more in our guides on machinability of materials et surface finishes for CNC machining.
What CNC Machining Materials Cost
Material cost comes from raw material price, grade, disponibilité, and machining waste. Machinability then adds labor and tooling cost.
- Aluminum and free-machining brass are usually the most cost-effective metals.
- Stainless steel costs more to buy and cuts slower than aluminum.
- Titanium costs more again, in both material and cycle time.
- COUP D'OEIL, Torlon, and Ultem cost more than ABS or Delrin and machine more slowly.
Exact prices depend on your geometry, grade, finition, and volume. A quote gives you the real number.
DFM Tips For Choosing A Machinable Material
Select the material before you finalize thin walls, fils de discussion, et les tolérances. Each material machines differently.
- Specify the grade and standard. Do not write only “aluminum” or “stainless steel”.
- Avoid deep pockets and thin walls in soft, gummy plastics.
- Match tight tolerances to machinability. Tight tolerances in titanium cost more.
- Decide on surface finish or coating before quoting. They change the material choice.
- Confirm temperature and chemical exposure before you pick a plastic.
When Not To Use Certain Materials
Some materials machine easily but fail in service. Others perform well but cost too much to machine.
- 6061 aluminum struggles in strong chloride or seawater environments.
- 304 stainless can gall and work-harden. Choisir 303 stainless steel when machinability is a higher priority; choisir 304 ou 316 when corrosion resistance is more important.
- Titanium is expensive and slow to machine. Use it only when weight or biocompatibility justifies it.
- PTFE and UHMW creep under load and are hard to hold to tight tolerances.
- Acrylic is brittle and cracks at sharp corners.
- Magnesium swarf is flammable and needs controlled machining.
- Plain carbon steel rusts. It needs coating or plating unless hardened or passivated.
Questions fréquemment posées
What materials can be CNC machined?
Metals such as aluminum, acier, acier inoxydable, titane, cuivre, laiton, et du magnésium, plus plastics such as ABS, acrylique, nylon, Delrin, COUP D'OEIL, and PTFE.
What is the best material for CNC machining?
It depends on the part. For most general-purpose parts, 6061-T6 aluminum is a strong default. Match the material to the load, environnement, et finir.
What is the most common CNC machining material?
6061-T6 en aluminium. Il allie la force, résistance à la corrosion, and fast machinability.
What is the easiest material to CNC machine?
Brass C360 and free-machining aluminum among metals. Delrin or acetal among plastics.
What is the strongest CNC machining material?
There is no single strongest CNC machining material. High-strength alloy steels, tool steels, and titanium alloys are commonly selected for demanding metal applications, while PEEK and Torlon are options for high-performance plastic parts. The right choice depends on tensile strength, dureté, température, porter, and load requirements.
Is aluminum cheaper to machine than stainless steel?
En général, Oui. Aluminum machines faster and wears tools less, so it costs less per part for most geometries.
Can hardened steel be CNC machined?
Oui. It needs rigid machines, carbide tooling, and slower feeds.
Do you provide material certificates?
Oui. Request a certificate for your specified grade when you Contactez-nous.
Get A Material Recommendation For Your Part
Nous usinons 100+ metals and plastics under an ISO 9001:2015 quality system. Our shop covers 3-axis, 4-axe, and 5-axis milling, tournant, et GED. We finish prototypes in 1–3 days and return quotes in 24 heures. Achievable tolerances depend on geometry, matériel, machine, et méthode d'inspection.
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