M270-35A (GB 35W270) costs more per ton than a standard 0.35mm grade from our non-oriented silicon steel line like 35W300, and the reason is narrow: it guarantees roughly 10% lower core loss at the same thickness — 2.70 W/kg versus 3.00 W/kg at P1.5/50. Whether that’s worth paying for depends entirely on what the motor
A 3.2 certificate isn’t a “better” 3.1 — it’s a 3.1 with a second, independent signature added on top. Both report the same test results for the same coil; the difference is who is allowed to vouch for those numbers, not what got measured. For electrical steel, that mill test certificate (MTC) is what turns
Most buyers asking “what is grain-oriented silicon steel” already have a transformer core spec in front of them and a supplier quoting a grade code they don’t fully trust. Fair enough — the short answer is this: grain-oriented silicon steel (GOES, also called CRGO — cold-rolled grain-oriented electrical steel) is a 3.0–3.5% silicon-iron alloy rolled
Non-oriented electrical steel grades split along two axes that a single grade code rarely makes obvious: whether the coil is semi-processed or fully processed, and which loss tier it sits in once it is fully processed. A “50W470” or “M400-50A” on a quote tells you thickness and a guaranteed loss ceiling — it does not
Hi-B grain-oriented steel costs more than standard CRGO for the same thickness. The question buyers actually need answered isn’t which one is “better” — it’s whether the core-loss savings pay back the premium fast enough to matter for a specific transformer. This article works through that math with real numbers from our own standard and
CRGO steel grades fall into four tiers: conventional grain-oriented (CGO), high-permeability Hi-B, domain-refined or laser-scribed Hi-B, and ultra-thin grain-oriented strip for higher frequencies. Each tier adds one specific metallurgical step — and one specific line of cost — over the tier below it, and the grade code on your quote is supposed to tell you
A CRGO coil is grain-oriented electrical steel that has passed through six controlled stages — hot rolling, cold rolling, decarburization annealing, high-temperature purification annealing with an MgO separator, insulation coating, and (for Hi-B grades) laser domain refinement — before it’s slit and shipped. Each stage sets a specific number on your mill test certificate: skip
Prime CRGO is first-quality mill coil, supplied with a per-coil EN 10204 3.1 mill test certificate and a guaranteed maximum core loss. Secondary CRGO — also sold as non-prime, “second and defective,” or lamination grade — is downgraded material: off-gauge or off-chemistry coil, edge trim and slit remnants, re-rolled stock, or sheet reclaimed from scrapped
On 27 March 2026 the European Commission opened a safeguard investigation into imports of grain-oriented electrical steel (GOES), and — unusually — into the laminations and cores made from it. If it ends in measures, the likely form is a tariff-rate quota, not a duty. That distinction changes how you plan orders, not just what
An amorphous core transformer typically costs 20-30% more upfront than an equivalent silicon steel unit, and pays that premium back through lower no-load losses — but the payback period ranges from under five years to never, depending almost entirely on how lightly loaded and how continuously energized the transformer actually is. That single variable, not
