Comparing electrical steel quotations from different suppliers can be confusing because the same general material category may be identified under different standards.

A European supplier may quote an EN or IEC grade, a Japanese mill may use a JIS designation, and a North American supplier may specify an ASTM grade. The grade names can look very different even when the materials have similar thicknesses and magnetic performance.

The important point is that electrical steel grades should not be compared by designation alone.

Key Points

Compare the steel type, nominal thickness and delivery condition before comparing magnetic performance.
Core loss values are only directly comparable when flux density, frequency and test conditions are comparable.
Grade designation systems differ across IEC/EN, JIS, GB/T and ASTM, so similar magnetic performance may appear under different grade names.
For material approval, check the applicable datasheet or specification together with magnetic properties, coating and guaranteed limits.

Why Electrical Steel Standards Use Different Grade Systems

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Electrical steel grade designation systems for IEC EN JIS ASTM and GB/T standards

IEC, EN, ASTM, JIS and Chinese GB/T standards were developed within different standardization systems, so their grade designations, reference conditions and specification structures are not always identical.

Some systems encode thickness and loss class directly in the grade name, while others use a different designation structure. Reference test conditions, including frequency, may also differ.

IEC / EN and JIS Grade Designations

IEC/EN and JIS non-oriented electrical steel grades often use similar information in a different order.

Grade	System	Nominal Thickness	Loss Class
M270-50A	IEC / EN	0.50 mm	2.70 W/kg
50A270	JIS	0.50 mm	2.70 W/kg

For M270-50A, “270” indicates the specified loss class and “50” indicates a nominal thickness of 0.50 mm. In 50A270, the same information appears in a different order.

These grades illustrate why similar materials may have different designations across standards. However, a matching thickness and loss class alone do not establish full equivalence; the applicable standard and test conditions still need to be checked.

Chinese GB/T Electrical Steel Standards

China uses national GB/T standards for electrical steel. For fully processed non-oriented electrical steel, GB/T 2521.1-2016 is an important product standard and is closely related to the IEC framework.

Buyers comparing GB/T grades with IEC, EN or JIS materials should focus on the same core parameters: nominal thickness, guaranteed core loss, flux density, frequency, delivery condition and other specified magnetic properties.

A similar grade designation or loss class should not be treated as proof of direct equivalence.

ASTM and Legacy AISI Designations

ASTM uses a different designation structure. ASTM A677 includes grades such as 36F155 and 47F165, while older AISI names such as M19 may still appear in supplier datasheets and industry discussions.

For ASTM A677 grades, classification is based on maximum core loss measured at 1.5 T and 60 Hz using the Epstein test method.

A legacy designation such as M19 therefore cannot be matched directly to an IEC, EN, JIS or GB/T grade without confirming the applicable ASTM specification, nominal thickness and guaranteed magnetic properties.

How to Compare Electrical Steel Grades Across Standards

A cross-standard comparison should begin with the technical requirements behind each grade, not with an assumed grade equivalent.

The following process can be used to compare quotations or datasheets from suppliers using different standards.

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Four-step method for comparing electrical steel grades across different standards

Step 1: Collect the Specification Behind Each Grade

Obtain the applicable standard, supplier datasheet or inspection certificate and compare:

grade designation and applicable standard;
electrical steel type and delivery condition;
nominal thickness;
guaranteed core loss together with flux density and frequency;
test method;
relevant polarization or permeability requirements;
coating or surface condition; and
guaranteed limits versus typical mill values.

Step 2: Put Core Loss Values Under Comparable Test Conditions

Core loss values should only be compared directly under comparable test conditions. A value measured at 1.5 T and 50 Hz, for example, should not be treated as directly equivalent to one measured at 1.5 T and 60 Hz.

Whenever possible, request supplier data at the same flux density and frequency. If this is unavailable, keep the original test conditions visible rather than applying a fixed frequency conversion factor.

Step 3: Compare the Grades Side by Side

A simple comparison table helps keep the original test conditions visible.

Grade	Standard	Type	Thickness	Maximum Core Loss	Flux Density	Frequency	Notes
M270-50A	IEC / EN specification as applicable	NGOES	0.50 mm	2.70 W/kg	1.5 T	50 Hz	50 Hz loss class; check full applicable specification
50A270	JIS	NGOES	0.50 mm	2.70 W/kg	1.5 T	50 Hz	Same nominal thickness and loss class; full equivalence not implied
47F165	ASTM A677	NGOES	0.47 mm	3.64 W/kg	1.5 T	60 Hz	ASTM classification uses different reference conditions

Note: The table illustrates the comparison process rather than declaring these grades fully equivalent. Final suitability depends on the complete magnetic, dimensional and delivery requirements.

Step 4: Check Whether the Grades Are Technically Interchangeable

Once the main test conditions have been aligned, check whether the proposed material meets the remaining application and acceptance requirements.

A lower core loss does not automatically make one grade a better substitute for another. Magnetic polarization or permeability, dimensional requirements, coating, processing conditions and guaranteed limits may also affect suitability.

The goal is not to rank grades by core loss alone, but to determine whether the proposed material can meet the same functional requirements.

In many cases, it is safer to describe a cross-standard grade as a possible alternative subject to technical approval rather than an exact equivalent.

Why Core-Loss-Based Pricing Can Help Buyers

Grade designations define a material category, but they do not always show the full value of the magnetic performance being supplied.

For buyers comparing quotations, core-loss-based pricing can make the relationship between performance and cost more transparent. Lower-loss material may justify a higher price, while a higher-loss grade may still be suitable where efficiency requirements are less demanding.

HWHG applies this approach to electrical steel quotations, allowing buyers to evaluate price together with the magnetic-loss performance required for the application.

HWHG electrical steel core loss evaluation for performance-based pricing

Conclusion

Electrical steel grades across IEC, EN, ASTM, JIS and GB/T systems can be compared, but not by grade designation alone. The comparison should be based on the technical requirements behind each grade, especially thickness, magnetic performance and test conditions.

For purchasing or material substitution, use the applicable standard and supplier datasheet to determine whether a proposed grade is technically suitable rather than assuming a direct one-to-one equivalent.

How to Compare Electrical Steel Grades Across IEC, EN, ASTM, JIS and GB/T Standards

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How to Read Electrical Steel Core Loss Test Conditions: P1.5/50 vs P1.7/50

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