20GK065 Grain-Oriented Electrical Steel — 0.20 mm, 0.65 W/kg
20GK065: what it is and where it belongs
20GK065 is the lowest-loss grade in our 0.20 mm range and the material most often used to certify Grade 1 oil-immersed distribution transformers on the first type test. Its guaranteed core loss of 0.65 W/kg leaves genuine margin against the no-load limit, while the 1.90 T flux density keeps the core cross-section compact — the two things that decide whether a rated unit passes.
Typical applications
Grade 1 oil-immersed distribution transformers (S20 / S22 class)
Urban compact substations with strict noise limits
High-specification export tenders requiring loss margin
Step-up units where lifetime energy loss is scored
Selection and processing notes
Highest unit price and longest lead time in the range: position it as a technical-bid advantage, not a volume grade.
If cost pressure dominates, 20GK070 gives the same thickness with 0.05 W/kg more loss headroom.
Supply form and documentation
Supplied as master coil 900–1250 mm wide (508 mm ID, 2–5 t per coil), slit strip from approximately 100 mm at ±0.5 mm width tolerance, or cut-to-length sheets to your lamination size. Standard insulation coating is C5, with C6 heat-resistant and chrome-free options. Every shipment carries an MTC to EN 10204 3.1 stating grade, heat number, measured core loss and flux density, plus packing list and — for export — certificate of origin and a standard cross-reference sheet against IEC 60404-8-7, ASTM A876, EN 10107 and JIS C 2553.
Equivalent designations
Nearest mill equivalent: B20R065. Buyers specifying to IEC or ASTM may treat this grade as the 0.20 mm, 0.65 W/kg tier; the equivalence sheet is supplied with the quotation so the substitution can be written into the purchase order without ambiguity.
