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JLY Precision Technology

알루미늄 CNC 가공: 완전 가이드 2026

CNC 알루미늄 가공 엔지니어 가이드: 6061 vs 7075 vs 2024, 가공성, 양극 산화, 비용, 리드 타임 및 설계 팁.

15 min read
Precision-machined 6061 aluminium components after Type II anodising

알루미늄은 CNC의 일꾼 — JLYPT 산업 작업의 약 70%가 일부 알루미늄 등급에서 실행됩니다. 이 가이드는 심층 분석: 어떤 작업에 어떤 합금, 어떤 공차가 현실적, 어떤 마감이 작동하는지.

Why aluminium dominates CNC

Aluminium hits a sweet spot of properties no other commodity material matches:

  • Light — about 1/3 the density of steel (2.7 g/cm³ vs 7.85). Critical for aerospace, drones, robotics.
  • Strong enough — 6061-T6 yields at 276 MPa, comparable to many mild steels.
  • Cuts fast — soft enough to remove material at 3–5× the rate of stainless or titanium.
  • Anodises beautifully — every colour, hard surface, integral to the part.
  • Conducts heat — ideal for heat sinks, electronics enclosures, LED housings.
  • Corrosion-resistant by default — the natural oxide layer protects without coating.
  • Recyclable — chips and offcuts have real scrap value, lowering net cost.

Alloy comparison — which one and why

Cost relative to 6061-T6 bar stock at standard sizes. Machinability rating: 1=worst, 5=best.
AlloyYield (MPa)MachinabilityAnodiseBest forCost
6061-T6276Excellent (3-rated)Yes — perfectDefault for 70% of work1.0×
6063-T5215ExcellentYes — best cosmeticExtruded profiles, decorative1.05×
7075-T6503Good (4-rated)Acceptable, mottledAerospace, motorsport, structural1.4×
7075-T651503GoodAcceptableStress-relieved 7075 for stable parts1.5×
2024-T351345GoodPoor (clad recommended)Aerospace skins, fatigue parts1.3×
5052-H32193ExcellentYesMarine, sheet-metal-style folded1.0×
5083215GoodYesMarine welded structures1.2×
MIC-6 / Cast tool170ExcellentYes (cosmetic mediocre)Vacuum chucks, optical bases, jigs1.6×
A380 die-cast160Tricky (porosity)DifficultCast housings (cnc finishing only)0.9×
CNC-machined aluminium components in different alloys
Standard JLYPT aluminium stock — 6061 and 7075 cover ~85% of customer requirements.

When 6061 is the right choice

  • General-purpose brackets, housings, plates.
  • Anything that needs cosmetic anodising.
  • Cost-sensitive work where strength is moderate.
  • Welded assemblies (6061 welds well).

When 7075 is worth the upgrade

  • Structural aerospace components (wing ribs, frames).
  • High-stress brackets that fail in 6061 testing.
  • Motorsport (fewer parts means weight matters more).
  • Where 80%+ more strength justifies the 40% cost.

Machinability and cycle times

Aluminium machines fast — but how fast depends on alloy choice and tooling. Indicative cycle times for a representative 50×50×25 mm bracket with moderate complexity:

Cycle times measured on a Mazak Variaxis i-700 with carbide tooling and flood coolant.
AlloyRoughing speedFinishing speedTool lifeTotal cycle (typical)
6061-T6Very fastVery fastLong8 min
7075-T6FastFastMedium11 min
2024FastFastMedium12 min
MIC-6 (cast tool plate)FastExcellentLong9 min
Stainless 316L (compare)SlowSlowShort38 min

Achievable tolerances on aluminium

Tighter on aluminium than on stainless because aluminium doesn't spring back.
FeatureStandard CNCPrecision CNCHigh-end (with care)
External dimensions±0.10 mm±0.025 mm±0.005 mm
Hole diameter (drilled)±0.05 mm±0.013 mm±0.005 mm
Hole diameter (reamed)±0.013 mm±0.005 mm±0.0025 mm
Surface finish (Ra)3.2 µm0.8 µm0.4 µm
Flatness (over 100 mm)0.05 mm0.013 mm0.005 mm
Concentricity / true position0.05 mm0.025 mm0.013 mm

Aluminium's thermal expansion (~23 ppm/°C) is roughly twice that of steel — so for ±0.005 mm tolerances on parts longer than 100 mm, JLYPT machines in a temperature-controlled cell. See our tolerances and GD&T guide for more.

Finishes that work on aluminium

Common — fast, cheap

  • As-machined + deburr — bare metal, lowest cost.
  • Bead blast — uniform matte texture, hides tool marks.
  • Type II anodise (decorative) — clear, black, blue, red, gold etc.
  • Brush finish — directional grain like appliance steel.

Premium — performance

  • Type III hard anodise — 60 HRC surface, wear resistance.
  • Chromate conversion (Alodine) — corrosion + paint primer.
  • Powder coat — thick, durable, any colour.
  • Electroless nickel plate — wear + uniform thickness.
Various finishes applied to aluminium CNC parts
Anodised, bead-blasted and powder-coated aluminium — each finish chosen for the part's function and environment.

Industry applications

  • Consumer electronics — laptop chassis, phone frames, camera bodies. 6061 + Type II anodise dominates.
  • UAV and drones — frames, motor mounts, gimbals. 7075 for structural, 6061 for non-critical. See UAV parts.
  • Aerospace — brackets, instrumentation housings, ground support. 7075 + 2024 dominate. See aerospace manufacturing.
  • Robotics — joint housings, drive arms, gripper bodies. 6061 + hard anodise common. See robotic parts.
  • Heat sinks & LED housings — 6061 or 6063 for thermal conductivity, anodised black for emissivity.
  • Optical & imaging — MIC-6 cast tool plate for dimensional stability over time.
  • Automotive prototypes — 7075 for race-car components, 6061 for OEM-grade prototypes.

Real cost ranges

Indicative pricing for a typical 50×50×25 mm aluminium bracket, anodised type II, batch quantities:

Indicative only — actual quotes depend on geometry, tolerances, finish complexity. Request a real quote on the <a href="/contact-us-online-cnc-machining-services">contact page</a>.
Quantity6061 unit cost7075 unit costPer-unit drop
1 (prototype)$95$130
10$28$42−71%
100$11$18−61%
1000$6.20$10−43%

Want to lower your aluminium part cost without redesigning? See our cost reduction guide — typical savings: 20–40% by relaxing tolerances, switching from 7075 to 6061 where possible, and consolidating setups.

Design tips that save money on aluminium

  1. Internal corner radii ≥ 1 mm — lets us use larger, faster end mills.
  2. Wall thickness ≥ 0.8 mm — thinner walls deflect during cutting.
  3. Use 6061 unless you have a strength reason to upgrade — saves 30–40% on material + machining.
  4. Specify Type II anodise unless hardness is required — Type III roughly doubles finish cost.
  5. Don't demand mirror polish on cosmetic surfaces — bead blasting before anodising looks great and costs less.
  6. Tolerance only critical features — use ISO 2768-mK default for non-mating dimensions.
  7. Add 0.3 mm chamfers to all external edges — eliminates manual deburring labour.
  8. Avoid pockets deeper than 4× tool diameter — deep pockets need slow finishing passes.

자주 묻는 질문

CNC 가공에 가장 일반적인 알루미늄 합금은?
6061-T6이 큰 차이로 — CNC 알루미늄 작업의 약 70%가 이를 사용합니다. 강도 테스트가 요구할 때만 7075로 전환.
6061처럼 7075를 양극 산화할 수 있나요?
네, 그러나 외관 결과가 눈에 띄게 나쁩니다 — 약간 얼룩지거나 균일하지 않은 색상.
알루미늄에서 얼마나 좁은 공차를 유지할 수 있나요?
주의를 기울이면 생산 등급 장비에서 ±0.005mm 달성 가능. 표준 작업은 ±0.025mm를 쉽게 유지.
알루미늄이 야외용으로 좋은가요?
네 — 노출된 알루미늄도 자가 치유 산화 층을 형성. 공격적 환경(해양)의 경우 양극 산화가 상당한 보호 추가.
가공된 알루미늄 부품을 용접할 수 있나요?
6061 및 5052는 잘 용접됩니다(TIG). 7075는 본질적으로 용접 불가 — 용접부에서 50%+ 강도 손실.
6061과 7075의 비용 차이는?
재료: 7075는 ~40% 더 비쌉니다. 가공: ~25% 더 느립니다. 총 비용: 7075 부품은 6061 대비 ~50% 더.
JLYPT가 MIC-6 공구판을 조달할 수 있나요?
네 — 일반 두께로 MIC-6을 재고합니다. 진공 척과 광학 베이스의 기본.
알루미늄은 플라스틱 CNC 부품과 어떻게 비교되나요?
알루미늄은 강도, 열전도율, 내구성에서 이깁니다. 플라스틱은 무게와 절연에서 이깁니다.

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저자 소개

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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