Transformer manufacturing - Promisteel Co., Ltd

Transformer Manufacturing Industry

CRGO Silicon Steel & Transformer Core Materials for Manufacturers

Promisteel supplies grain-oriented electrical steel (CRGO) for transformer manufacturers, core processors and international electrical-equipment buyers. Our portfolio includes CRGO silicon steel coils and sheets, with slitting and cutting services discussed against the required grade, magnetic performance, thickness, width and delivery form. Share your transformer design requirements and we will review the applicable material and processing scope before quotation.

CRGO silicon steel coils, slit strips and export packing for transformer manufacturing

Real product and factory views of CRGO coils, processing and export-ready material.

Quick Answer: Why Is CRGO Steel Used in Transformer Cores?

Grain-oriented electrical steel is commonly used for the magnetic cores of power and distribution transformers because its magnetic properties are optimized along the rolling direction. Buyers should specify the applicable grade and standard, guaranteed core-loss test condition, thickness, insulation coating, usable dimensions, and the intended cutting or core-building process. Finished-transformer no-load loss cannot be guaranteed from coil-grade data alone.

CRGO Materials and Supply Forms We Support

Promisteel discusses CRGO silicon steel and transformer-core requirements with manufacturers and processors. Assembled cores are inquiry-led and require confirmation of drawings, fabrication scope and acceptance criteria.

Packed CRGO silicon steel coils for transformer core manufacturing

CRGO coil supply is reviewed by grade, thickness, magnetic data, coating and delivery dimensions.

Coils, Sheets and Slit Material

Choose the supply form around your production route and equipment. Review CRGO silicon steel coils for slitting and lamination production, or compare the dimensional options on the

CRGO silicon steel sheet page.

The final offer depends on the verified grade, dimensions, magnetic requirements and processing scope.

Supply form	Procurement use	What to confirm
CRGO silicon steel coils	Input material for transformer-core slitting and lamination production	Grade, coil width, thickness, loss values, coating and coil ID/OD
CRGO silicon steel sheets	Cut-to-length or sheet-based core fabrication	Sheet dimensions, flatness, edge condition and rolling direction
Slit CRGO strips	Core shops using narrower feedstock	Slit width, burr limits, tolerances and handling
Transformer core / lamination requirements	Application-specific discussion; not a blanket promise of assembled-core production	Core drawing, geometry, step-lap design and whether fabrication is available

Typical Transformer Applications

Where CRGO Materials Are Used

Distribution transformers
Power transformers
Dry-type and oil-immersed transformers
Transformer core shops and electrical-steel service centers

Transformer magnetic core application using grain-oriented electrical steel

Finished transformer performance depends on the complete design and manufacturing process, not coil-grade data alone.

Application boundary: Promisteel is a material-supply partner, not the transformer designer or certifier. Selection of the final transformer performance class remains with the OEM and its engineering team.

Specifications Transformer Buyers Should Confirm

Published CRGO sheet examples include 0.20, 0.23, 0.27, 0.30 and 0.35 mm thicknesses and 900–1200 mm widths. Coil-page examples include 0.27 mm grades 27P105 and 27P120. These values illustrate product scope and do not guarantee current availability.

Parameter	RFQ requirement	Why it matters
Nominal thickness	Specify 0.23 / 0.27 / 0.30 / 0.35 mm or other verified offer	Influences lamination count, processing and loss
Magnetic grade	Named grade, standard and revision	Avoids non-equivalent substitutions
Specific total loss	Guaranteed W/kg at named flux density and frequency	Meaningful only with a defined test condition
Magnetic induction / excitation	Required measurement and acceptance limits	Affects core magnetization and design
Insulation coating	Type, resistance and thermal compatibility if required	Supports interlaminar insulation and downstream processing
Dimensions	Coil/sheet width, tolerance, weight and ID/OD	Must fit slitting, cutting and handling equipment
Edge and surface	Burr, camber, flatness, scratches and coating condition	Impacts assembly quality and usable yield
Documentation	Inspection certificate, traceability, test report and packing list	Supports incoming quality control and claim handling

Supply Network and Processing Coordination

Slit CRGO electrical steel strips on a processing line

Slitting feasibility, width tolerance, camber and burr limits must be confirmed for the requested material.

Processing Is Confirmed Against the RFQ

We focus on grade sourcing, coil allocation, slit-width feasibility, cutting scope, export packing and scheduling. Potential slitting and cutting services must be checked for material compatibility, minimum and maximum widths, burr tolerance, tooling, MOQ and lead time.

The PromiSiS electrical steel portfolio provides additional context for CRGO and CRNGO applications.

Core and Lamination Requirements

Transformer core and lamination discussions require a drawing, geometry, step-lap design and an agreed fabrication boundary. Cutting stress, joint design, stacking, annealing and assembly can all affect finished-core performance.

These requirements are reviewed case by case; no general claim of assembled-core availability or finished-transformer performance is made.

Transformer core laminations and slit CRGO steel

Core geometry and lamination requirements are drawing-led and must be confirmed before quotation.

Quality and Acceptance Planning

CRGO silicon steel coil surfaces and supply forms

Material identity and guaranteed magnetic values must refer to the agreed grade and test condition.

Define Measurable Acceptance Criteria

Confirm material identity and traceability, the standard revision, dimensions and edge condition, magnetic test values with named test conditions, insulation coating, packing and document requirements.

Checks may include dimensions, surface/coating, edge and burr condition, and magnetic reports. Third-party inspection can be discussed where permitted. The exact test location and responsibility should be stated rather than assumed.

Agree how deviations, substitutions, rejection criteria and claims will be handled.
Match each guaranteed value to its test method, flux density, frequency and document.
Keep coil and slit-batch identification visible through receiving and core production.

Export Packing and Delivery Planning

Protect Edges, Coating and Traceability

CRGO packing should address moisture, edge protection, handling and coating protection. Confirm package weight, coil ID, transport route, container constraints and unloading equipment before packing is finalized.

Agree guards, skid or pallet design, coil orientation, labels, net/gross weights and shipping marks. Incoterms, port, document set, inspection hold points, readiness date and partial-shipment rules should be stated in the order.

CRGO coils protected and packed for export shipment

Export packing should protect edges, coating and material condition through the agreed transport route.

Why Transformer Manufacturers Work with Promisteel

This page is part of Promisteel's broader serviced-industries material support for manufacturers and international buyers.

Application-Focused Sourcing

Material discussions start from transformer and core-processing requirements.

Multiple Supply Forms

Coils, sheets and slit material can be reviewed against the intended production route.

Processing Coordination

Slitting and cutting scope is checked against tooling, tolerance, MOQ and schedule.

Documentation-Led Purchase

Acceptance criteria, traceability and test documents are aligned before order.

International Commercial Support

Export packing, shipping documents and Incoterms are coordinated with the buyer.

These are service processes and do not represent claims of certified transformer efficiency, permanent inventory or universal transformer-core manufacturing capability.

Transformer Steel RFQ Checklist

Transformer application and destination market
Required CRGO grade and applicable standard
Thickness and guaranteed loss/test condition
Insulation coating requirement
Coil, sheet, slit strip or core/lamination inquiry

Width, tolerance, coil ID/OD and package weight
Trial and annual/recurring volume
Destination port and Incoterm
Documents, inspection and target delivery window
Core drawing or transformer material datasheet

Frequently Asked Questions

What is CRGO steel used for?

CRGO steel is commonly used in magnetic cores for distribution and power transformers because its magnetic properties are optimized along the rolling direction.

Can Promisteel supply both CRGO coils and sheets?

Yes. Coils and sheets are part of the published product scope, subject to grade, dimensions, quantity and availability confirmation.

Can you supply slit CRGO strips?

Slitting can be discussed, but slit width, tolerance, burr limit, camber, tooling and minimum order quantity must be confirmed.

What CRGO thicknesses are available?

Published examples include 0.20, 0.23, 0.27, 0.30 and 0.35 mm. The available offer must be verified for the requested grade and dimensions.

What magnetic data should buyers request?

Request the guaranteed specific total loss at a stated flux density and frequency, plus any required induction or excitation values and the applicable test standard.

Does the CRGO grade alone guarantee transformer no-load loss?

No. Finished-transformer loss also depends on cutting stress, joint design, stacking, annealing where applicable, assembly and the complete transformer design.

Can Promisteel provide transformer iron cores?

Core or lamination requirements can be reviewed from drawings, but fabrication scope, geometry, step-lap design and acceptance criteria must be confirmed for each inquiry.

What information is needed for an export quotation?

Send the application, grade/standard, magnetic test conditions, coating, thickness, dimensions, supply form, quantity, destination, Incoterm, document and inspection requirements, and target delivery window.

Send Your Transformer Steel Requirements

Share your grade, magnetic-performance requirement, thickness, width, supply form, quantity, processing need and destination. Promisteel will review the applicable CRGO material and processing scope before quotation.

Request a CRGO quotation