Western Machine Works


Precision Machining – Trunnion Yoke & Hubs

Trunnion yoke and hubs were machined to OEM specifications within a 3-day emergency timeline. The components were part of a hydro dam assembly that required urgent repair.  


  • Part: Trunnion Yoke + Hubs (2x)
  • Details: Hub assembly and yoke were heat treated per AWS D1, 5
  • Customer: Industrial Equipment Manufacturer


  • Emergency response and round-the-clock machining schedule.
  • Complex pre-machining setup.
  • Stringent technical specifications for the bore dimensions, height dimensions, tolerances, and Ra finishes.

Engineered Solutions:

Trunnion Yoke:

  • Machine base plate prior to machining to ensure flatness.
  • Line bore holes per print and ensure parallelism.
  • Machine surfaces per print and Ra finish.
  • Drill and tap 4 places on the side.
  • Machine 2 drain pockets on the base.
  • Record dimensions prior to and after machining.

Trunnion Hubs (2x):

  • Setup in vertical and ensure bottom face is true.
  • Machine top of hubs per OEM print.
  • Machine bore per OEM print.
  • Record height dimensions, tolerance, and Ra finish before and after machining.


  • All OEM specifications were achieved.
  • Completed all machining within a 3-day rush repair schedule.
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