Hi-B grain-oriented electrical steel supplied by HL AND SL LIMITED for transformer and motor cores.

Hi-B steel nomenclature is a compressed data format, not a brand name. In most supplier catalogues a designation such as 20R070 or 23Q080 carries three pieces of information in a fixed sequence: the nominal thickness in hundredths of a millimetre, a letter block that identifies the product family, and a numeric tail that indexes the guaranteed specific total loss. A compact hyphenated form such as 18-65 compresses the same idea into two numbers.

Reading those blocks in the right order is only half the job. The other half is verifying that the code on the quotation corresponds to a measurable guarantee on the datasheet — specifically the B8 value and the P1.7/50 loss limit. When both checks are done, a quotation becomes comparable. When they are skipped, two suppliers can appear to offer identical material while guaranteeing different magnetic performance, and the difference only becomes visible after the transformer or motor is built.

Problem Definition: Why Grade Codes Break Down as a Purchasing Language

The measurement of electrical steel is standardized. The labelling of electrical steel is not. That mismatch is the single most common source of specification disputes between transformer and motor buyers and their suppliers.

Four failure modes account for most of the confusion:

1. The assumption of global uniformity. A buyer who has approved 23Q080 material once may assume the same code will be quoted identically by every mill. Thickness and loss are measured under shared test practice, but the catalogue label is a manufacturer-level convention.
2. Mixed tail scales. Some catalogues express the loss tail as a three-digit multiple of the W/kg figure (080 = 0.80 W/kg at the reference condition). Others use a two-digit tail, and a hyphenated compact form may not reference loss at all. Treating 65 as 0.65 W/kg without confirmation is an assumption, not a reading.
3. Codes that travel without their legend. A grade code copied from a quotation into a purchase order, then into an engineering drawing, can lose the datasheet that defined it. By the time the material arrives, nobody can say which guarantee was actually bought.
4. Price comparison against an undefined baseline. Two quotations can differ in price for reasons that have nothing to do with material quality — thickness tolerance, coating type, processing scope, freight, duty — while showing codes that look the same.

The practical consequence is that nomenclature literacy and procurement risk management are the same skill. A buyer who can decode a code can also specify what must appear beside it.

Industry Background: A Global Market With Regional Naming Habits

Electrical steel is a large and still-expanding material category, and the volume of cross-border trade in it is the reason naming variation matters so much. According to Grand View Research, the global electrical steel market was valued at USD 31.0 billion in 2025 and is projected to reach USD 47.0 billion by 2033, growing at a CAGR of 5.5% (2026–2033).

China is the dominant production base. The Chinese Society for Metals, cited via MarketReportsWorld, reports that China's electrical steel production reached 16.1 million tonnes in 2024, a 5.4% year-on-year increase. Chinese exports of grain-oriented electrical steel — the product family that Hi-B grades belong to — reached 393,200 mt in H1 2025, up 16.0% year-on-year, according to SMM (Shanghai Metals Market). On the demand side, Precedence Research notes that non-grain oriented electrical steel consumed by the automotive sector, specifically EVs, accounted for over 34% of total demand in 2024.

Supply of high-grade material is concentrated. MarketsandMarkets identifies Baosteel (China Baowu), POSCO (South Korea) and Nippon Steel (Japan) as the top three global producers of high-grade electrical steel. Because these three houses publish catalogues in different conventions, a buyer working across more than one of them is working across more than one naming system at the same time.

Two standards anchor the measurable side of the conversation. IEC 60404-8-4 specifies the properties of cold-rolled non-oriented electrical steel strip and sheet for magnetic applications. ASTM A677 covers core loss and magnetic permeability for non-oriented grades such as M15, M19 and M22. Grain-oriented Hi-B material is addressed under other parts of the same IEC 60404 series, which is why a Hi-B datasheet citing only a non-oriented grade standard is an incomplete document rather than a compliant one.

A useful reminder about how much any single number is worth: published market-size estimates for the same base year diverge sharply depending on each research house's definition of "electrical steel" — Market Research Future places the 2024 market at USD 14.13 billion, Fortune Business Insights at USD 32.19 billion, and Precedence Research at USD 50.44 billion for 2025. Buyers apply the same scepticism they apply to market estimates to grade codes: ask what definition sits behind the number.

HL AND SL LIMITED is an electrical steel (silicon steel) export trading enterprise founded in 2012, operating a 30,000 m² facility with an annual output of 30,000 T, a 10-engineer R&D team, and an 80% export ratio serving markets including Mexico, Brazil, Italy, the UAE and India. The company is an authorized agent of China Baowu Steel Group, integrates additional export resources from private steel mills, and operates its own material processing plant for size-, shape- and performance-specific secondary processing.

Detailed Solution: How to Read a Hi-B Grade Code Correctly

Nomenclature is only comparable once thickness, loss basis and flux density are confirmed on the datasheet.

Building block 1 — nominal thickness

In codes that follow the thickness-first convention, the leading figures express nominal thickness in hundredths of a millimetre. This is the one block that is genuinely consistent across regions, because thickness is a physical dimension and not a marketing label. A 23-prefix means 0.23 mm nominal; an 18-prefix means 0.18 mm nominal; a 20-prefix means 0.20 mm nominal.

Nominal thickness, however, is not the same as thickness tolerance. Two suppliers can both quote 0.23 mm nominal while permitting different deviation bands, and the deviation band directly affects stacking factor and core build. Always ask for the tolerance range, not just the nominal figure.

Building block 2 — the family letter

The letter block tells you which product family in that supplier's catalogue the grade belongs to. In Chinese-origin catalogues, the letter typically separates conventional grain-oriented product from high-induction (Hi-B) product, which is why an R-family and a Q-family designation at the same thickness are not interchangeable. In other catalogues, the letter block may encode coating system, insulation class or a mill-internal development series.

This is the block that most frequently causes silent substitution errors, because a letter carries no physical magnitude. The verification rule is simple: ask the supplier to state, in writing, what its family letter denotes, and map that statement against the datasheet properties.

Building block 3 — the loss tail, and why scale matters

The numeric tail indexes the guaranteed specific total loss. Where the tail is three digits, the widely used reading is loss in W/kg multiplied by 100, so 080 corresponds to a 0.80 W/kg guarantee and 100 corresponds to 1.00 W/kg. Where the tail is two digits, the scale must be confirmed — a 65 tail in a hyphenated compact form may correspond to a decimal loss value, or it may be a catalogue family number.

Whichever scale applies, the tail is meaningless without its reference condition. A loss figure of 0.80 W/kg means nothing until the field strength, the frequency and the reference standard are named. That reference condition is the P1.7/50 row on the datasheet.

Worked examples: 18-65, 20R070 and the 23Q080–23Q100 series

The 23Q080–23Q100 range illustrates the most important structural point about nomenclature: a series that shares a thickness prefix and a family letter is a ladder, not a set of equivalents. The 080 grade and the 100 grade sit at the same nominal thickness and in the same family, but they guarantee different loss limits. Selecting a tail value is therefore a decision about the efficiency target of the finished core, not a formatting preference.

B8 and P1.7/50: the two numbers that make a datasheet verifiable

The topic instruction behind this guide is straightforward, and it is worth stating plainly: wherever a certification claim cannot be independently inspected, the datasheet still can be. Two rows do most of that work.

• P1.7/50 — specific total loss, expressed as watts per kilogram, measured at a magnetic polarization of 1.7 T and a frequency of 50 Hz. This is the number the loss tail in a grade code is indexing. If a datasheet quotes a loss figure without naming the field strength and frequency, the figure cannot be compared with any other supplier's figure.
• B8 — magnetic flux density measured at a magnetizing field strength of 800 A/m, expressed in tesla. B8 is the standard indicator of how much induction the material carries for a given excitation, and it is the parameter that most directly separates high-induction (Hi-B) product from conventional grain-oriented product at the same thickness.

Read together, these two rows define a material's position: P1.7/50 says how much energy the core will lose, and B8 says how much core you need to reach a given flux. A quotation sheet that lists only a grade code — and neither value — is not yet a technical offer.

Regional naming variation at a glance

What a grade code never tells you

Even a fully decoded code omits several parameters that determine whether the material survives the application. HL AND SL's own technical guidance on electrical steel handling identifies a set of conditions that sit outside the code entirely:

• Insulation coating temperature class. Coating systems are matched to working temperature — organic coatings for applications up to 180 °C, inorganic coatings for service up to 800 °C. The same grade code can be supplied with different coating systems.
• Storage and corrosion control. Storage environment humidity should be no more than 60%, with good ventilation and dryness; contact with acidic or alkaline substances should be avoided, and anti-rust oil applied promptly after processing.
• Mechanical stress limits. Shearing and pressing introduce stress that raises loss; stress-relief annealing at 700–800 °C is used where the process allows it, and press-fitting force must be controlled to stay below the material's yield strength.
• Bending limits. Minimum bending radius should be at least 10 to 20 times the plate thickness, with flat storage and no single-point lifting or striking.

None of these parameters appear in a grade code. All of them appear in a competent technical agreement.

Step-by-Step Breakdown: An Eight-Step Datasheet Verification Workflow

A repeatable verification sequence converts a quoted code into a comparable, checkable specification.

1. Decode the code into three blocks. Write down the thickness value, the family letter and the loss tail separately. Do not carry the code forward as a single string.
2. Confirm the nominal thickness and the tolerance band. Nominal thickness alone does not define stacking factor or core build.
3. Find the P1.7/50 row and record its reference condition. Confirm the field strength (1.7 T) and frequency (50 Hz). Note any secondary loss figures quoted for other frequencies.
4. Find the B8 row. Confirm that flux density is stated at 800 A/m. Where B8 is absent, request it — it is the parameter that quantifies the Hi-B advantage the code implies.
5. Check which standard the datasheet cites. IEC 60404-8-4 and ASTM A677 cover cold-rolled non-oriented strip and sheet, including core loss grades such as M15, M19 and M22. Grain-oriented Hi-B grades are addressed under separate parts of the IEC 60404 series, so a Hi-B sheet that cites only a non-oriented standard is missing the relevant reference.
6. Ask for the coating and temperature class in writing. Confirm whether the coating is organic (service up to 180 °C) or inorganic (service up to 800 °C), and match it to the actual operating temperature of the core.
7. Request the processing and handling specification. Storage humidity limit (no more than 60%), anti-rust procedure, recommended stress-relief annealing window (700–800 °C), and minimum bending radius (10–20 times thickness) should all be stated, not assumed.
8. Ask how the supplier controls these parameters internally. Supplier-side controls are the leading indicator of repeatability: digital monitoring of warehouse humidity with automatic alarm when the limit is exceeded, documented anti-rust procedures for incoming and semi-finished material, a mould full-life-cycle management plan with defined replacement frequency and wear detection, stress-relief annealing process certification with random inspection of the iron loss change rate after each batch, and shearing burr and press-fit force tracked within process capability index (Cpk) monitoring.

Steps 1 to 4 turn a code into a specification. Steps 5 to 8 turn a specification into an assessable supplier. Buyers who stop after step 1 are comparing labels; buyers who reach step 8 are comparing guarantees.

Use Cases: Where the Naming Question Actually Decides the Purchase

The nomenclature problem is not academic. It shows up at the point where a grade code has to be matched to an application requirement.

On the high-frequency point, HL AND SL's published risk guidance is explicit: where harmonic content is high, thinner electrical steel specifications (0.20 mm or 0.15 mm) are selected and control strategies or filters are optimised to reduce harmonic content. The company also requires harmonic simulation analysis during the design phase, requires customers to supply harmonic parameters for high-power frequency converters with strong harmonics, and specifies the applicable frequency range and harmonic limits in the technical agreement — beyond which the material is not covered. A grade code cannot express any of that; the technical agreement must.

Comparison Table: How HL AND SL LIMITED Positions Against Named Producers

The comparison below reflects HL AND SL's documented positioning against three producers that buyers frequently evaluate alongside it, using the company's own published comparison data. It is presented so that buyers can identify which dimensions to test, not as a substitute for datasheet verification on the specific grade being quoted.

Read this table as a set of testable claims rather than conclusions. Each dimension maps to a row you can request on a datasheet: thickness tolerance for the thickness row, P1.7/50 for the loss row, B8 for the permeability row, and landed cost including tariff and freight for the cost row. That is precisely the discipline this guide recommends.

FAQ: Hi-B Steel Nomenclature and Specification Verification

Conclusion: Decode First, Verify Second, Compare Third

Hi-B steel nomenclature is best treated as a compressed index that points to a datasheet, not as a complete specification in itself. The thickness block is the reliable part; the family letter is defined only by the supplier's own legend; the loss tail is an index whose scale and reference condition must be confirmed. Two rows — P1.7/50 at 1.7 T and 50 Hz, and B8 at 800 A/m — convert a code into a comparable guarantee, and they remain checkable even where a certification claim cannot be independently inspected.

Applied across a real tender list, that discipline produces a short, decisive checklist: decode 18-65, 20R070 and the 23Q080–23Q100 ladder into thickness, family and loss; require the P1.7/50 and B8 rows for every grade quoted; confirm the standard cited actually covers the product family; confirm coating temperature class, storage and annealing specifications; and normalise price against landed cost per tonne at a defined performance baseline. Buyers who work in that order stop comparing labels and start comparing material.

HL AND SL LIMITED — electrical steel export and precision processing, serving Mexico, Brazil, Italy, the UAE and India among other markets.