The 4.70 W/kg workhorse of the non-oriented family — 0.50 mm fully processed silicon steel for laminations that must spin cool and convert efficiently, from EV traction motors to distribution transformers.
Non-oriented grades trade core loss against cost and induction. 50WW470 is where most motor programs land — better than 600/700/800, without paying for the 400/350 step.
50WW400 shaves core loss to 4.00 W/kg with higher silicon and tighter processing — roughly 15% lower loss for premium efficiency programs. 50WW470 keeps induction and punchability at lower cost. For an EV motor chasing the last efficiency point, the 400 step earns its premium; for most, it does not.
Choose 400 when the efficiency target forces it; 470 otherwise.The 600/700 rungs cost less and punch faster, but loss climbs to 6.0–7.0 W/kg — motors run hotter and efficiency drops. They suit pumps, fans and fractional-horsepower motors where loss is secondary to material cost.
Choose 470 when the machine is continuous-duty or efficiency-rated.0.35 mm 300-grade halves the loss for high-frequency traction and aerospace work but costs more, stacks slower and needs tighter die control. 50WW470 remains the value rung for 50 Hz / low-to-mid frequency designs.
Choose thin high-grade for high-frequency; 470 for 50 Hz volume.Typical values for the NO electrical steel base — silicon is the key alloying element. Confirmed on the MTC.
| Element | Typical range (%) |
|---|---|
| Silicon (Si) | 1.0 – 2.0 |
| Carbon (C) | ≤ 0.005 |
| Manganese (Mn) | 0.20 – 0.60 |
| Phosphorus (P) | ≤ 0.08 |
| Sulfur (S) | ≤ 0.005 |
| Aluminium (Al) | 0.20 – 0.50 |
Typical, confirmed on MTC. Final chemistry reflects the target core loss and induction band.
The numbers that decide whether a motor meets its efficiency label — per GB/T 2521.1 and IEC 60404 test methods.
| Property | Guaranteed | Notes |
|---|---|---|
| Core loss P1.5/50 | ≤ 4.70 W/kg | Max, at 1.5 T, 50 Hz — the grade number |
| Core loss P1.0/50 (typ.) | ≤ 1.90 W/kg | Indicative, at 1.0 T, 50 Hz |
| Magnetic induction B50 | ≥ 1.72 T | At 5000 A/m |
| Stacking factor (typ.) | ≥ 0.96 | Depends on coating and edge condition |
Indicative. Core loss and induction are confirmed on the MTC by Epstein or single-sheet test per your governing standard.
Electrical steel is specified magnetically; mechanicals are indicative and matter mainly for die life and stacking.
| Property | Typical value | Notes |
|---|---|---|
| Yield strength (typ.) | 230 – 320 MPa | Higher silicon raises strength, lowers punchability |
| Tensile strength (typ.) | 380 – 480 MPa | Indicative |
| Elongation (typ.) | 22 – 32% | Indicative |
| Hardness (typ.) | 130 – 180 HV | Indicative — drives die wear in lamination punching |
Indicative only; mechanical values are not the acceptance criterion for electrical steel.
Same property class, different naming — confirm guaranteed values and test method before substitution.
| Standard | Grade | Notes |
|---|---|---|
| GB (China) | 50WW470 | Base reference — GB/T 2521.1 |
| JIS (Japan) | 50A470 (approx.) | Confirm against JIS C2552 |
| IEC | M470-50A (approx.) | Confirm against IEC 60404-8-4 |
| Baosteel (China) | B50A470 (approx.) | Same property class, mill naming |
| ASTM (USA) | No direct 50 Hz grade equivalent | ASTM A677 grades are 60 Hz-based — compare measured loss, not designation |
Approximate, confirm before substitution. Always compare guaranteed core loss, not the name.
0.50 mm punched stator laminations with segment slots, stress-relief annealed and coated. Core loss at 1.5 T/50 Hz sets the drive-cycle efficiency — 470-grade keeps the motor cool at continuous torque.
Rotor laminations punched from the same slit coil, stacked and skewed. Consistent gauge and stacking factor hold rotor balance and the air-gap tolerance that decides NVH.
E and I laminations for small distribution and isolation transformers. The 470 band balances no-load loss against core cost — the economic choice for standard-efficiency units.
Continuous-duty stators in generators, compressors and pumps where heat from core loss shortens insulation life. 470-grade keeps winding temperature down without a premium material cost.
Read this before you order, so the grade matches the machine duty.
Use 50WW470 when your machine is continuous-duty, efficiency-rated, or frequency-driven — EV traction motors, generators, compressors, distribution transformers — and the design allows a 0.50 mm stack. It is the volume grade: enough silicon to keep loss at 4.70 W/kg, enough induction (≥ 1.72 T) to keep the stack compact, and good punchability for high-speed lamination dies.
Do not use it when the machine runs at high frequency (above roughly 1 kHz, where thin high-grade like 35WW300 pays back), when the priority is absolute cost per ton for a short-duty appliance (50WW600/700 then), or when the application needs grain-oriented steel — transformer cores carrying flux in one direction only should be discussed separately, as grain-oriented grades are a different family.
Pair it with HC180YD+Z bake hardening steel for the EV body structure around the motor, 22MnB5+AS for motor-mount crash members, and SAPH440 for the drivetrain brackets — one supplier covering the magnetic core and the structural shell.
Narrow slit widths with controlled edge burr — burr on electrical steel raises inter-lamination shorting and loss. Edge condition is inspected, not assumed.
Supplied with the standard insulating coating (C-class organic/semi-organic) that separates laminations after stacking; coating type is matched to your anneal route.
We specify the anneal cycle (approx. 730–790 °C, protective atmosphere) that restores magnetic performance after punching without degrading the coating.
Laser-cut prototype laminations from the same coil, so motor validation runs on the same material as production punching.
Stay with 50WW470 while the machine meets its efficiency target and the die punches cleanly. Move up to 50WW400 (or 35WW-series for high frequency) when measured loss fails the label target — the premium is justified by the efficiency class, not by feel. Move down to 50WW600/700 only for short-duty, cost-driven machines where heat is not a life issue. If your motor is rated against JIS or IEC, order by the equivalent grade name (50A470 / M470-50A) but keep the guaranteed core loss as the acceptance criterion — that is the number that matters, whichever standard prints it.
Hysteresis vs eddy-current loss, how silicon and gauge change them, and how to read an Epstein test certificate.
Why punching raises core loss, what the stress-relief cycle does, and which coatings survive it.
HS-FINEB steel grades matched to motors, generators and transformers.
From electrical coil to ready-to-punch lamination strip.
These grade families share material, processing or application territory with the topic on this page.
Invar / Kovar / Elinvar / Nichrome precision alloys for electromagnetic, thermal-bimetal and resistance applications.
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