CNC İşleme Malzeme Seçim Rehberi 2026
Uygulamaya göre CNC malzeme seçimi için pratik rehber. Alüminyum, paslanmaz, titanyum, pirinç, plastik — değişimleri açıklanmış.
Malzeme seçimi genellikle CNC parçanın maliyetini, ağırlığını, işlenebilirliğini ve son kullanım performansını etkileyen tek en büyük karardır. Bu rehber JLYPT'nin günlük olarak işlediği malzemelerin nereye ait olduğunu — atölye zemininden yazılmış olarak — gösterir.
How to think about material choice
Most material decisions can be reduced to four questions, in order:
- Mechanical requirements — yield strength, fatigue, stiffness, weight target, operating temperature.
- Environment — corrosion, chemicals, UV, food/medical contact, sterilisation cycles.
- Machinability and cost — how fast it cuts, how much the bar stock costs, what tooling wear to expect.
- Finishing and downstream processes — does it anodise, plate, weld, paint, glue?
Aluminium alloys — the workhorses
Aluminium dominates CNC work because it cuts fast, takes a beautiful surface, anodises in any colour, and weighs a third as much as steel. For most consumer and industrial parts, the question is which aluminium alloy, not whether to use aluminium.
| Alloy | Yield (MPa) | Best for | Trade-off |
|---|---|---|---|
| 6061-T6 | 276 | General-purpose: housings, brackets, fixtures | Moderate strength; most common |
| 6063-T5 | 215 | Extruded profiles, decorative anodised parts | Softer; slightly worse machined finish |
| 7075-T6 | 503 | Aerospace, motorsport, structural | Harder to machine, less corrosion resistant, anodises poorly |
| 2024-T351 | 345 | Aerospace skin, fatigue-loaded parts | Susceptible to stress corrosion; usually clad |
| 5052 | 193 | Marine, sheet-metal-style folded brackets | Lower strength but excellent corrosion resistance |
| MIC-6 / cast tool | 170 | Vacuum chucks, optical bases, tooling plates | Stable but heavy; rarely used for end-use parts |
Carbon and stainless steels
When strength, fatigue resistance or corrosion in aggressive environments matters, steel is the answer. Three families cover almost everything we machine:
Carbon & alloy steels
- 1018, 1045 — cheap, weldable, easy to machine. Good for shafts, jigs, low-stress brackets.
- 4140, 4340 — pre-hardened or heat-treatable to ~50 HRC. Used for gears, drive shafts, tool holders.
- Will rust without coating — plate, paint or oil.
Stainless steels
- 303 — free-machining, but worse corrosion resistance and not weldable.
- 304 — the default food/marine grade.
- 316L — superior corrosion resistance, medical-implant grade.
- 17-4PH — precipitation-hardened, ~40 HRC, aerospace and pumps.
- 15-5PH — similar to 17-4 with better transverse properties.
For surface treatment of steel parts, see our surface finishing services — passivation for stainless, black oxide for tool steel, electroless nickel for carbon steel.
Titanium and superalloys
Titanium and nickel superalloys are the answer when no other material works — typically aerospace, medical implants, downhole oil tools and high-end motorsport.
| Material | Strength | Density (g/cm³) | Typical use |
|---|---|---|---|
| Ti-6Al-4V (Grade 5) | 895 MPa | 4.43 | Aerospace structural, bicycle frames, surgical implants |
| CP Titanium (Grade 2) | 275 MPa | 4.51 | Chemical processing, marine |
| Inconel 718 | 1240 MPa | 8.19 | Jet engine hot section, downhole tools |
| Inconel 625 | 760 MPa | 8.44 | Marine seawater, chemical processing |
| Hastelloy C-276 | 690 MPa | 8.89 | Worst-case chemical environments |
| Monel 400 | 241 MPa | 8.80 | Seawater, hydrofluoric acid |
Brass, bronze and copper
Copper-based alloys are niche but indispensable for electrical, plumbing and decorative work.
- C360 brass (free-machining). Cuts like butter, ideal for valves, fittings, electrical components and decorative hardware.
- C932 bearing bronze. Self-lubricating; bushings, gears, marine fittings.
- C110 (oxygen-free copper). Best electrical and thermal conductivity; bus bars, heat sinks, RF.
- Beryllium copper (C17200). Springs, non-sparking tools, EMI gaskets — but requires careful handling due to dust hazards.
Engineering plastics
CNC-machined plastics fill applications where metal is too heavy, too conductive or too expensive. Sheet stock and extruded rod are routinely turned and milled to ±0.05 mm tolerances.
| Material | Strengths | Watch out for |
|---|---|---|
| Delrin / POM | Low friction, dimensional stability, machines cleanly | Difficult to glue; weak in UV |
| Nylon (PA6, PA66) | Wear resistance, gears, bushings | Absorbs moisture and grows ~2% |
| PTFE (Teflon) | Chemical inert, very low friction, –200 to +260°C | Soft, creeps under load |
| Polycarbonate (PC) | Optical clarity, impact resistance | Scratches easily; chemical sensitive |
| Acrylic (PMMA) | Optical clarity, easy to polish | Brittle, not for impact |
| PEEK | Aerospace/medical, –60 to +250°C, autoclavable | Very expensive (~$300/kg bar stock) |
| UHMW-PE | Wear resistance, chemical inert, food-safe | Difficult to machine to tight tolerance |
For micro-features in plastics — sub-millimetre walls, optical surfaces — see our micro-machining services.
Materials at a glance
A condensed reference for selecting a starting material based on your top requirement:
| Top requirement | Start with | Upgrade path |
|---|---|---|
| Cheap and good enough | 6061 aluminium | 7075 → 17-4PH |
| Strength-to-weight | 7075 aluminium | Ti-6Al-4V |
| Corrosion resistance | 316L stainless | Hastelloy C-276 / Monel |
| Wear resistance, low friction | Hardened 4140 + DLC coat | Tool steel (D2, A2) |
| Heat resistance (>500°C) | Inconel 625 | Inconel 718, Waspaloy |
| Electrical conductivity | C110 copper | Silver-plated copper |
| Thermal conductivity (heat sinks) | 6061 aluminium | C110 copper |
| Optical clarity | Acrylic (PMMA) | Polycarbonate |
| Food contact / sterilisation | 316L stainless | PEEK for plastics |
| Magnetic permeability needed | 1018 carbon steel | 4140 hardened |
| Non-magnetic (MRI rooms) | 316L stainless or Ti | Beryllium copper |
Material × finish compatibility
The chosen surface finish often constrains the material. Always check both before locking the design:
| Finish | Compatible materials | Not compatible |
|---|---|---|
| Type-II anodising (decorative + protection) | 6061, 6063, 5052 | 7075 (poor cosmetic finish) |
| Type-III hard anodising | 6061, 7075, 2024 | 5xxx series (some grades) |
| Bead blasting | Most metals and plastics | Anything that must remain optical |
| Powder coating | Aluminium, steel, stainless | Plastics (heat-sensitive) |
| Electropolishing | Stainless 316L, 304 | Carbon steel |
| Black oxide | Carbon and tool steels | Stainless (only specific grades) |
| PVD coating | Stainless, tool steel, carbide | Aluminium (substrate softens at coating temp) |
Read more about specific finishes in surface finishing and PVD coating.
Sıkça Sorulan Sorular
- Alüminyum 6061 büyük farkla. Çubuk stoku ucuz, hızlı kesilir ve herhangi bir standart kaplama kabul eder. JLYPT'nin endüstriyel işlerinin yaklaşık %70'i 6061'dir.
- Çoğu evet, ancak farklı takımlarla. Titanyum ve nikel süper alaşımları daha yavaş kesim hızları ve keskin takımlar gerektirir. Magnezyum özel yangın söndürme gerektirir.
- Pratik açıdan: Ti-6Al-4V yorulma dahil edildiğinde 7075 alüminyumu hafifçe geçer. Saf çekme mukavemeti-ağırlık için modern karbon fiber kompozitler kazanır.
- Anodize rengi alaşıma, banyo kimyasına ve zamanlamaya bağlıdır. Aynı parti = iyi eşleşme. Farklı partiler = küçük varyasyon. Kritik işler tek partide işlenmelidir.
- Parça sürekli neme, tuza veya kimyasallara maruz kalacaksa paslanmaza gidin. Kuru iç mekanlar için galvanizli/boyalı karbon çelik çok daha az maliyetlidir.
- Çoğu zaman hayır. 3D baskılı bir Ti-6Al-4V parça, CNC işlenmiş olandan farklı bir malzeme sınıfıdır. Sertifikalı havacılık veya tıbbi işler için ikisi ayrı yeterlilik olmadan değiştirilemez. CNC vs 3D karşılaştırmasına bakın.
- Evet — yaygın alaşımları (6061, 7075, 304, 316L, Ti Grade 5, Delrin, PEEK) stokta tutuyoruz ve tam Malzeme Test Raporları (MTR) ve uygunluk sertifikaları ile özel malzemeleri tedarik edebiliriz.
En ucuz CNC işleme malzemesi nedir?
Tüm malzemeleri aynı ekipmanda işleyebilir miyim?
En iyi mukavemet-ağırlık oranına sahip malzeme hangisi?
Anodize alüminyumum partiler arasında renk eşleşecek mi?
Paslanmaz mı yoksa kaplı çelik mi gerekli?
3D baskılı malzemeler CNC işlenmiş olanlarla değiştirilebilir mi?
JLYPT benim için malzeme tedarik edebilir mi?
Yazar hakkında
JLYPT Engineering Team
Senior CNC Application Engineers
Our application engineering team brings 15+ years of combined experience producing precision components for aerospace, medical, robotics and industrial automation customers.
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