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Complex Parts CNC Machining Services

DEK runs complex parts CNC machining for designs turned down elsewhere, holding ±0.003 mm on micro features. 50+ metals and engineering plastics run under one ISO-certified roof.

  • ±0.003mm

    Micro Features

  • 50+

    Metals & Plastics

  • 3 Days

    Fast Prototypes

5-axis CNC machining complex aluminum part with deep internal cavities
ISO Certified ISO 9001, ISO 13485, AS9100D
Complex CNC machining finished aluminum housing with dense features

Complex CNC Machining for Parts Others Turn Down

Complex CNC machining covers geometries that push a standard 3-axis setup past its limits: thin walls that chatter, deep cavities beyond tool reach, compound angles, dense features and tight tolerance stacks across mating features.

DEK stacks 5-axis CNC machining, turning, EDM and grinding under one quality system, so a thin-wall housing, deep-cavity manifold or compound-angle bracket moves between operations in-house instead of bouncing between vendors.

Why Engineers Choose DEK

Complex parts fail sourcing when a shop can do four operations and subs out the fifth. Here is what keeps them on track at DEK.

  • Two Decades of Practice

    A production floor built on two decades of hands-on precision-machining work, serving a client base of 2,300+ global OEMs sourcing complex work.

  • 1.2 Million Parts a Year

    More than 1.2 million critical parts leave DEK's shop floor every year, with in-house CMM inspection and full traceability documentation on every job.

  • 98.6%+ On-Time Delivery

    On-time delivery holds above 98.6% across that volume, with milling, turning, EDM and grinding run in-house under one quality system.

  • No MOQ, 3-Day Prototypes

    No MOQ: one-off complex prototypes run alongside production orders, with prototype lead time as fast as 3 days.

Engineer-Reviewed Drawings

Every quote comes from an engineer who has reviewed the drawing, not an automated calculator. Send 2D/3D drawings and call out the tolerances that matter most: you get a review, not a bounce.

Multi-Process Capability Stack

A single machine rarely solves a genuinely complex part. These processes run under one roof so each operation stays in-house.

  • 3-, 4- and 5-Axis CNC Milling

    Axis count is chosen by geometry: extra axes only where they remove a setup or reach a feature.

    • 3-axis for flat faces, pockets and simple contours
    • 4-axis for features around a cylindrical body
    • 5-axis for compound angles and deep-cavity access
    • ±0.01 mm profile control on 5-axis work
    Multi-Axis Machining
    Parameter Specification
    3-axis Flat faces, pockets, contours
    4-axis Rotary features, no 2nd setup
    5-axis Compound angles, one clamping
    5-axis complex profile ±0.01 mm
  • CNC Turning and Swiss Machining

    Rotational features are turned, and slender parts go to Swiss machines to avoid deflection.

    • Rotationally symmetric shafts, sleeves and housings
    • Swiss machining for long, slender parts
    • Sub-10 mm diameters that would deflect on a lathe
    CNC Turning Services
    Parameter Specification
    CNC turning Shafts, sleeves, housings
    Swiss machining Long, slender parts
    Swiss part diameter Sub-10 mm
    Micro / sub-10 mm tolerance ±0.003 mm
  • EDM, Grinding and Gear Machining

    These processes finish what cutting tools cannot reach or hold after heat treatment.

    • Sinker and wire EDM for hardened alloys
    • Internal corners no cutting tool can reach
    • Cylindrical grinding for coaxial shaft-bore fits
    • Gear machining for integrated teeth and splines
    Cylindrical Grinding
    Parameter Specification
    Sinker and wire EDM Hardened alloys, inner corners
    Cylindrical grinding Shaft-bore fits after heat treat
    Fit-critical coaxiality ±0.005 mm
    Gear machining Teeth and splines in one body
  • Tolerances for Complex Parts

    These numbers hold across the whole process stack, not just the primary milling operation.

    Precision Machining
    Parameter Specification
    General CNC machining ±0.005 mm
    5-axis complex profile ±0.01 mm
    Micro / sub-10 mm parts ±0.003 mm
    Fit-critical (coaxiality) ±0.005 mm
    Part size range Up to ~1000 mm
  • Quality System for Complex Parts

    Complex parts carry more risk of a missed feature or an out-of-spec fit, so every job runs through documented QMS stages.

    • ISO 9001, AS9100D and ISO 13485, obtained through TUV
    • IQC, IPQC, FAI, OQC, SPC and CAPA stages
    • In-house CMM inspection and full traceability
    Learn About Quality
    Parameter Specification
    Certifications ISO 9001, AS9100D, ISO 13485
    Certified through TUV
    QMS stages IQC, IPQC, FAI, OQC, SPC, CAPA
    Inspection In-house CMM
    Documentation Full traceability, every job

Complex Parts Machining vs. Single Processes

Choose complex parts CNC machining when a design combines two or more difficulties; see CNC machining cost for how each process drives price.

Criteria This ProcessComplex Parts CNC Machining 3-Axis Machining EDM Machining Swiss Machining
Best for Multi-feature, multi-process Flat faces and pockets Hardened alloys Long, slender parts
Geometry Thin walls, cavities, angles Straightforward contours Unreachable inner corners Sub-10 mm diameter
Typical tolerance ±0.003 to ±0.01 mm ±0.005 mm (general) Per drawing ±0.003 mm (micro)
Choose when 2+ difficulties combine Extra axes add cost only Milling can’t finish feature Part deflects on a lathe

Industries Running Complex Parts

Aerospace (non-flight-critical cabin and structural parts), medical devices, robotics and semiconductor equipment run complex parts through DEK.

What Makes a Part Complex to Machine

A part usually qualifies when it combines two or more of these features. Together, they narrow the list of shops that can run it.

  • Thin Walls

    Walls that flex or chatter under cutting load, typical of thin-wall housings where a free-machining grade helps avoid deflection.

  • Deep Cavities & Pockets

    Cavities beyond standard tool reach, reached in one clamping with 5-axis CNC machining or finished by EDM.

  • Compound Angles

    Multi-axis angles that need simultaneous tool tilt, as on compound-angle brackets, machined without re-fixturing.

  • High Feature Density

    Many holes, bosses or pockets in one body, run in a single program without rework or repeated setups.

  • Tight Tolerance Stacks

    Stacked tolerances across mating features, with fit-critical shaft-bore and coaxiality held to ±0.005 mm.

  • Multi-Process Builds

    Multi-material or multi-process parts milled, ground and EDM'd in the same body, finished with cylindrical grinding.

Common Challenges We Handle

  • Designs Turned Down

    Thin-wall housings, deep-cavity manifolds and multi-material assemblies with stacked tolerances get an engineer review, not a bounce.

  • Hardened Deep Cavities

    A deep-cavity part in a hardened alloy may need EDM to finish features milling can't reach; validated on Ti-6Al-4V, Inconel 718 and 17-4PH.

  • The Subcontracted Fifth Step

    Complex parts fail sourcing when a shop does four of five operations and subs out the fifth; DEK keeps the full stack under one roof.

  • Bores Ground After Turning

    A coaxiality-critical bore ground after turning still has to land inside ±0.005 mm, or the assembly doesn't go together.

Quality Built for Complex Parts

Certified through TUV, with in-house CMM inspection and full traceability on every job.

  • AS9100D and ISO 9001 certification logo
    AS9100D

    Aerospace Quality Management System

  • ISO 9001 certification logo
    ISO 9001:2015

    Quality Management Standard

  • ISO 13485 certification logo
    ISO 13485

    Medical Devices Quality Management

How to Order Complex Machined Parts

  • 1

    Send Drawings

    Send 2D/3D drawings, material and quantity, and call out the tolerances that matter most.

  • 2

    Engineer Review

    An engineer reviews the drawing before quoting, not an automated calculator; no MOQ applies.

  • 3

    Confirm Order

    Quote, details and delivery schedule confirmed; prototypes can ship in as little as 3 days.

  • 4

    In-House Production

    Milling, turning, EDM and grinding run in-house under one quality system, not across vendors.

  • 5

    Inspect & Ship

    IQC, IPQC, FAI and OQC with in-house CMM and full traceability documentation, then shipment.

Frequently Asked Questions

Straight answers on cost, tolerances and ordering for complex machined parts.

How much does CNC machining cost per hour?
There's no single hourly rate: cost depends on the process (milling vs. turning vs. EDM), material, tolerance and volume for your specific part. Our cost guide, linked in the comparison section above, breaks down what drives price up or down.
What makes a part complex to machine?
A part usually qualifies when it combines two or more of these: thin walls that flex or chatter, deep cavities beyond tool reach, compound angles, high feature density, tight tolerance stacks across mating features, or multi-material and multi-process builds.
What tolerances can DEK hold on complex parts?
We hold ±0.003 mm on micro and sub-10 mm parts, ±0.005 mm on general CNC machining and fit-critical shaft-bore or coaxiality features, and ±0.01 mm on 5-axis complex profiles, on parts up to about 1000 mm.
Is there a minimum order quantity for complex parts?
No. There's no MOQ: one-off complex prototypes run alongside production orders, and prototypes can ship in as little as 3 days. Every quote comes from an engineer who has reviewed the drawing.

Request a Complex Parts CNC Machining Quote

Send 2D/3D drawings and call out the tolerances that matter most. Talk with our experts about the part other shops turned down.

  • No MOQ, from one-off prototypes
  • Prototypes ship in as little as 3 days
  • Every quote reviewed by an engineer
  • Tolerances as tight as ±0.003 mm
  • ISO 9001, AS9100D and ISO 13485
Request an Aerospace Quote