Low Iron Loss Non Oriented Steel

Low Iron Loss Non Oriented Steel Benefits

4 June, 2026 News

Low iron loss non oriented steel (CRNGO) saves energy in every motor that spins. Yet, “low loss” means different things depending on frequency and thickness. A motor running at 50 Hz cares about one loss component; a high-speed EV motor cares about another. Here is how iron loss actually breaks down, and how buyers specify the right grade.

Two Loss Sources, Two Fixes

Iron loss splits into two parts:

Hysteresis loss comes from friction as magnetic domains flip each cycle. Chemistry and grain size control it.
Eddy current loss comes from circulating currents induced in the steel. Thickness controls it.

Consequently, a high-efficiency motor needs both: a clean chemistry for low hysteresis, and thin gauges for low eddy current.

Grade Numbers: What P₁.₅/₅₀ Actually Means

CRNGO grades are defined by core loss at 1.5 T, 50 Hz:

Grade	Thickness	P₁.₅/₅₀ max	Typical use
M19	0.50 mm	3.5 W/kg	Premium motors, generators
M27	0.50 mm	4.2 W/kg	Standard industrial motors
M36	0.50 mm	5.2 W/kg	General-purpose
M43	0.50 mm	7.0 W/kg	Cost-sensitive, low-duty

Lower number = lower loss = higher price. Specify the grade that meets your efficiency class (IE3, IE4), not the cheapest one.

Thickness: The Eddy Current Lever

Eddy current loss scales with the square of thickness. Consequently, cutting thickness from 0.50 mm to 0.35 mm reduces eddy current loss by about 50%. At 400 Hz (high-speed motors), that difference becomes huge. For 50 Hz industrial motors, 0.50 mm is fine. For variable-frequency or high-speed drives, 0.35 mm or thinner pays back.

The Efficiency Class Logic

Modern motor standards (IE3, IE4, IE5) set minimum efficiency. To meet IE4, you typically need M19-grade 0.35 mm CRNGO. To meet IE3, M27 or M36 at 0.50 mm works. Consequently, specify your motor’s efficiency class first, then pick the grade that meets it.

low iron loss non oriented steel

Where CRNGO Saves Money

A 100 kW motor running 8,000 hours per year wastes 3–5% more energy with M43 than with M19. Over a 15-year life, that difference adds up to thousands of dollars in electricity. The premium for M19 pays back within months.

CRNGO Products We Supply

We stock non-oriented silicon steel in standard grades:

M19 Non-Oriented Electrical Steel in 0.50 mm for premium motors and generators.
M43 Non-Oriented Electrical Steel in 0.50 mm for cost-sensitive general-purpose motors.
50W1300 Non-Oriented Electrical Steel as a lower-grade option for auxiliary and low-duty motors.

Specify the Grade and Thickness

A complete order reads: “M19, 0.50 mm, P₁.₅/₅₀ ≤ 3.5 W/kg, C-5 insulation coating, slit to 950 mm.” Leave out the grade and you receive whatever stock is cheapest.