A usinagem CNC funciona com duas amplas famílias de materiais: metais e plásticos. Sua escolha de material define força, peso, resistência à corrosão, maquinabilidade, acabamento superficial, e custo. The right choice always depends on the part’s loads, ambiente, 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, produtos químicos, umidade, ultravioleta, and food or medical contact.
- Propriedades mecânicas.Define required strength, dureza, rigidez, e resistência ao impacto.
- Maquinabilidade.Estimate how fast and cleanly the material cuts.
- Acabamento superficial.Decide on as-machined roughness, anodização, revestimento, ou revestimento.
- Custo.Compare raw material price, tempo de ciclo, e desgaste da ferramenta.
Material Grade And Condition Matter
The alloy name alone is not always enough when you specify a CNC machining material. Temperamento, tratamento térmico, dureza, and material condition can significantly affect strength, maquinabilidade, estabilidade dimensional, e custo.
- Alumínio 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.
- Aço inoxidável 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. Recozido 4140 machines easily. Endurecido 4140 is stronger but slower and more expensive to cut.
Specify the full grade, temperamento, and condition on your drawing. That one line removes ambiguity in quoting, usinagem, e inspeção, and it lets the shop match the correct material certificate.
CNC Machining Metals
Metals dominate CNC work because they deliver strength, tolerâncias apertadas, and repeatable finishes.
| Material | Graus comuns | Principais vantagens | Aplicações Típicas |
| Alumínio | 6061-T6, 7075-T6 | Leve, usinável, resistente à corrosão | Aeroespacial, eletrônicos, automotivo |
| Aço | 1018, 4140, 4340, aço para ferramentas | Força elevada, hardenable, difícil | Eixos, ferramentas, peças estruturais |
| Aço inoxidável | 303, 304, 316, 17-4 PH | Resistente a corrosão, higiênico, forte | Médico, comida, marinho |
| Titânio | Nota 5 (Ti-6Al-4V) | Excelente relação resistência-peso, biocompatível | Aeroespacial, médico |
| Cobre | C110 | Excelente condutividade | Componentes elétricos |
| Latão | C360 | Free-machining, condutor | Acessórios, conectores |
| Bronze | C932 | Resistente ao desgaste, baixa fricção | Buchas, rolamentos |
| Magnésio | AZ31B | Very low density and excellent strength-to-weight potential | Lightweight housings |
| Zinco | os fardos 3 | Baixo custo, dimensionalmente estável | Peças pequenas |
| Ferro fundido | Cinza, dúctil | Vibration damping, resistente ao desgaste | Bases de máquinas, ferramentas |
6061-Alumínio T6 is one of the most widely used CNC machining materials for general-purpose structural and mechanical parts. Usar 7075 alumínio when you need higher strength. Escolher 304 ou 316 aço inoxidável for corrosion and hygiene. Escolher titânio when its strength-to-weight ratio, resistência à corrosão, Biocompatibilidade, or temperature performance justifies the higher material and machining cost. Liga de aço e aço para ferramentas suit high-strength and wear applications.
CNC Machining Plastics
Plastics are chosen for light weight, isolamento elétrico, resistência química, or lower cost.
| Plástico | Why Engineers Choose It |
| abdômen | Difícil, baixo custo, fácil de usinar |
| Acrílico (PMMA) | Claro, rígido, polishes well |
| Nylon (PA) | Forte, resistente ao desgaste |
| Delrin / Acetal (POM) | Stiff, baixa fricção, Excelente máquina |
| OLHADINHA | Alta resistência e resistência ao calor |
| PTFE | Baixa fricção, resistência química, suitable for many food-contact applications |
| Policarbonato (computador) | Difícil, transparente, resistente a impactos |
| PEAD / UHMW-PE | Baixa fricção, resistente a produtos químicos |
| PPS | High heat and chemical resistance |
| Ultm (PEI) | Flame-resistant, força elevada |
| Torlon (PAI) | Very high strength at temperature |
Delrin e nylon cover most general-purpose plastic parts. Usar OLHADINHA ou Ultm for high-temperature or medical work. PTFE e PEAD suit chemical and food-contact service. Acrílico gives you transparent, polished parts.
Quick CNC Material Selection Guide
| If you need… | Consider… |
| Low cost and easy machining | 6061 alumínio, latão, Delrin |
| Alta relação resistência-peso | 7075 alumínio, titânio |
| Resistência à corrosão | 316 aço inoxidável, titânio |
| Condutividade elétrica | Cobre, latão, alumínio |
| Resistência a altas temperaturas | OLHADINHA, PEI, PPS |
| Baixa fricção | POM, PTFE, UHMW-PE |
| Resistência ao desgaste | Tool steel, POM, UHMW-PE |
| Transparência | Acrílico, policarbonato |
| Medical applications | 316L stainless steel, titânio, OLHADINHA |
CNC Machining Materials By Application
| Aplicativo | Material To Consider | Por que |
| Aeroespacial | 7075 alumínio, titânio, OLHADINHA, Ultm | Strength-to-weight and heat resistance |
| Médico | 316L stainless, titânio, OLHADINHA | Biocompatibility and cleanability |
| Food Contact | 304/316 inoxidável, Delrin, PTFE, PEAD | Lavável, non-toxic surfaces |
| Elétrica | Cobre, latão, alumínio | Condutividade |
| Alta temperatura | Titânio, aço para ferramentas, OLHADINHA, Torlon | Resistência ao calor |
| Chemical Service | 316 inoxidável, PTFE, PEAD, PPS | Resistência química |
| Prototipagem | 6061 alumínio, abdômen, Delrin | Fast and low cost |
| Wear Parts | Hardened tool steel, Delrin, UHMW-PE | Resistência ao desgaste |
Machinability And Surface Finish
Machinability describes how easily a material cuts. It drives cycle time, Desgaste da ferramenta, terminar, e custo.
- Free-machining materials.Brass C360, 303 inoxidável, 6061 alumínio, and Delrin cut fast and finish well.
- Difficult materials.Titânio, Aço endurecido, 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 e surface finishes for CNC machining.
What CNC Machining Materials Cost
Material cost comes from raw material price, nota, disponibilidade, 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.
- OLHADINHA, Torlon, and Ultem cost more than ABS or Delrin and machine more slowly.
Exact prices depend on your geometry, nota, terminar, and volume. A quote gives you the real number.
DFM Tips For Choosing A Machinable Material
Select the material before you finalize thin walls, tópicos, e tolerâncias. 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. Escolher 303 stainless steel when machinability is a higher priority; escolher 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.
perguntas frequentes
Quais materiais podem ser usinados CNC?
Metals such as aluminum, aço, aço inoxidável, titânio, cobre, latão, e magnésio, plus plastics such as ABS, acrílico, nylon, Delrin, OLHADINHA, 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, ambiente, e terminar.
What is the most common CNC machining material?
6061-Alumínio T6. Combina força, resistência à corrosão, 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, dureza, temperatura, vestir, and load requirements.
Is aluminum cheaper to machine than stainless steel?
Geralmente, sim. Aluminum machines faster and wears tools less, so it costs less per part for most geometries.
Can hardened steel be CNC machined?
Sim. It needs rigid machines, carbide tooling, and slower feeds.
Do you provide material certificates?
Sim. Request a certificate for your specified grade when you Contate-nos.
Get A Material Recommendation For Your Part
Nós maquinamos 100+ metals and plastics under an ISO 9001:2015 quality system. Our shop covers 3-axis, 4-eixo, and 5-axis milling, girando, e EDM. We finish prototypes in 1–3 days and return quotes in 24 horas. Achievable tolerances depend on geometry, material, máquina, and inspection method.
Send your CAD, PDF, or sample drawing for a free DFM review and material recommendation.
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