The #1 US-owned power transformer manufacturer in North America Core type transformers up to 500 MVA, 525kV Shortest lead time in the industry Shell type power transformers up to 1400MVA 500kV The most reliable transformers made right here in the USA


Each power transformer is custom designed and the tolerances on winding coil dimensions are in millimeters. In addition, our design philosophy requires the elimination of sharp edges on all insulating parts (wood structures, spacers, rings, etc.). Our stringent process requires customizing insulating parts, this is achieved using a 5-axis milling machine. Onsrud’s 5-axis is used to manufacture internal wood supports, structures, and insulation components. This machine is computer-controlled for accuracy, and can manufacture directly from AutoCAD, Inventor, and Master Cam 3-dimensional drawings. We also have a 3-axis milling machine for other insulation components.

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