# Grain-oriented electrical steel & amorphous cores (transformers)

Part ID: 10.03 · Layer 10 (Materials & upstream inputs)

Grain-oriented electrical steel and amorphous metal alloy used to build the laminated cores inside power, distribution and instrument transformers.

The core of a transformer is a stack of thin steel or amorphous-alloy laminations that carries the magnetic flux linking the primary and secondary windings; the grade of that material sets the transformer's efficiency and, increasingly, how long it takes to build one. Grain-oriented electrical steel (GOES) is the standard material for larger power and distribution transformers; amorphous alloy cores are used where no-load losses matter most. This sits directly upstream of every transformer in the power chain — utility and substation transformers, unit substations and pad-mounted transformers feeding the building, and the smaller transformers inside power distribution equipment (Layer 6).
Production is concentrated among a small number of specialty steel mills that run dedicated GOES lines, and a shift toward amorphous cores draws on an even narrower alloy-supply base. Utilities and data-center developers have been buying transformers years ahead of need, and the taxonomy identifies GOES supply itself — not transformer manufacturing capacity — as the binding constraint behind those lead times. For investors, the questions are mill capacity additions (GOES lines are slow and capital-intensive to build), the pace of qualification for new suppliers, and exposure to Cleveland-Cliffs, named in the taxonomy as the sole US GOES producer, versus the larger number of international mills.

**AI delta:** GOES supply is the input constraint behind transformer lead times.

**Supply status:** tight

## Companies

| Company | Role | Confidence | Ownership | Ticker | Note |
|---|---|---|---|---|---|
| ArcelorMittal | manufacturer | inferred | public | MT |  |
| Baosteel | manufacturer | inferred | public | 600019.SS |  |
| Cleveland-Cliffs | manufacturer | inferred | public | CLF | sole US GOES producer |
| JFE | manufacturer | inferred | public | 5411.T |  |
| Nippon Steel | manufacturer | inferred | public | 5401.T | Nippon Steel / US Steel |
| POSCO | manufacturer | inferred | public | 005490.KS |  |
| Shougang | manufacturer | inferred | public | 000959.SZ |  |
| thyssenkrupp | manufacturer | inferred | public | TKA.DE | Electrical Steel |
| Proterial | manufacturer | inferred | private |  | amorphous |

Confidence tags: disclosed = company/filing statement; reported = trade press or partner list; inferred = taxonomy lead.