Uptower See all →
Private: Brake Disc Repair Damaged brake disc sections milled out and replaced uptower. Private: Generator Shaft Repair Worn generator shafts machined back to tolerance in place. No generator replacement. Private: Yaw Gear Mounting Flange Repair Worn yaw drive mounting flanges and damaged threads repaired uptower. Private: Yaw Sliding Surface Refurbishment On-site refurbishment of worn yaw sliding surfaces. No yaw ring exchange, no crane. Yaw Ring Teeth Repair Patented in-nacelle machining. The ring is repaired where it stands - no removal, no crane. Rotor Lock Repair Full rotor lock seat restoration in-nacelle. No component removal required. Bolt Removal & Thread Repair Failed or seized bolts removed and threads recovered without replacing the host component.
Blade See all →
Private: Blade Surface Milling 3D milling of damaged blade areas to an exact surface - uptower or on ground. Blade Root Repair Restore damaged blade root inserts onsite, reducing downtime from months to days Private: Blade Root Bushing Replacement Worn or fatigued blade root bushings replaced in-situ without scrapping the blade.
Support Structures & Flanges See all →
Monopiles & TPs Sub-millimetre flatness on monopiles and transition pieces. Precision machining performed before installation. Tower Flanges Tower section flange flatness restored on-site. No re-fabrication, no transport. Sea Fastening Machining sea fastenings and towers stands to the required tolerances without transporting the structures to a workshop.
General Industry See all →
Line Boring Portable line boring for large bores in-situ. Heavy industry, marine, energy. Axle & Shaft Repair Worn or damaged axle and shaft journals restored on-site. No removal, no replacement. Industrial Flange Machining Sub-millimetre flatness restored on site for industrial flanges on large production machinery. 3D Laser Measurement 3D laser tracker and Easy Laser services. Alignment verification, quality control, dimensional inspection on-site. High precision measurement.
Measurements See all →
3D Laser Measurement 3D laser tracker and Easy Laser services. Alignment verification, quality control, dimensional inspection on-site. High precision measurement.
Custom Solutions Can't find your repair? We design bespoke solutions for unique turbine geometries.
→
Flange Solutions

Support Structures &
Flange Solutions

Onsite precision machining of monopiles, transition pieces, tower flanges and sea fastening - restoring flatness, geometry and delivering tolerances well below industry requirements.

Flange Milling

Precision At Scale.

As wind turbine structures continue to grow, achieving precise flange geometry becomes increasingly challenging – and increasingly important.

Even minor deviations in large-diameter flanges can affect bolt preload, structural fit, fatigue performance, and long-term reliability.

CNC Onsite delivers precision machining of large-scale flanges for monopiles, transition pieces, tower flanges, and sea fastenings. Through controlled CNC machining, we achieve sub-millimetre flatness and uniform contact surfaces that support reliable bolted connections and reduce the need for corrective work during assembly.

Our documented results include:

  • < 1.0 mm global flatness and < 0.2 mm local flatness on transition piece flanges
  • 0.21 mm global flatness achieved on a 7.5-metre tower flange
  • < 1.0 mm global flatness and < 0.2 mm local flatness guaranteed machine performance

The result is a predictable manufacturing process that improves assembly quality, bolt performance, and long-term structural reliability.

Structures & Flanges services

Everything we do for Structures & Flanges

  • <0.2mm or 1mm globally flatness tolerance
  • Up to 10m Flange diameter
  • On site Or workshop-based
Speak to an engineer

Get expert advice on your project

Send us your damage report or turbine type and we'll respond within one working day with an assessment and indicative quote.

Jesper Nielsen
Your direct contact Jesper Nielsen Sales Director - North America +45 31 47 67 48 jen@cnconsite.dk

Damage photos help - email them directly or attach them when we reply.

Flange Milling

Why Choose CNC Onsite for Flange Milling

  1. 01

    Industry-Leading Flatness

    Achieve sub-millimetre flatness on large-diameter flanges, with documented results down to 0.21 mm.

  2. 02

    Reduced Rework & Post-Processing

    Replacing manual rework with a controlled CNC machining process that delivers repeatable results and quality.

  3. 03

    Documented Precision At Scale

    Documented performance well beyond industry standards on the largest flanges in the wind industry.

  4. 04

    Reduced Lifecycle Costs

    Better flange fit helps reduce maintenance requirements, corrective actions, and future bolt-related issues.

Trusted by wind operators and OEMs across Europe and North America

  • Vestas
  • Siemens Energy
  • NextEra Energy
  • GE Vernova
  • Enercon
  • Nordex
  • EDF Renewables
  • Welcon
  • RWE
  • CS Wind
  • EEW
  • Muehlhan
  • Nicon Industries
  • Orsted
  • Cadeler
  • Vattenfall
  • Smulders
  • Windar
  • Titan Wind
  • SubC Partner
  • Semco Maritime
  • LM Wind Power
  • Iberdrola
  • Vestas
  • Siemens Energy
  • NextEra Energy
  • GE Vernova
  • Enercon
  • Nordex
  • EDF Renewables
  • Welcon
  • RWE
  • CS Wind
  • EEW
  • Muehlhan
  • Nicon Industries
  • Orsted
  • Cadeler
  • Vattenfall
  • Smulders
  • Windar
  • Titan Wind
  • SubC Partner
  • Semco Maritime
  • LM Wind Power
  • Iberdrola
Explore more

OTHER CNC ONSITE SOLUTIONS

Talk to our team

READY TO TALK ABOUT YOUR Structures & Flanges PROJECT?

Get a feasibility assessment and indicative quotation within one business day.

Discuss your project