When transformer manufacturers evaluate a transformer core, attention often goes first to the CRGO steel grade.
The steel grade is important, but it is only one part of the final core performance.
Even high-grade CRGO can deliver disappointing results if the core is poorly cut, stacked or assembled.
For this reason, choosing the right transformer core manufacturer requires more than comparing raw material specifications. Manufacturing precision directly affects magnetic performance, dimensional accuracy and final transformer efficiency.
Burr Height Affects Interlaminar Performance
During CRGO cutting, excessive burr can damage the insulation coating between laminations.
This may increase local eddy currents and create additional losses.
For precision transformer core manufacturing, burr height should be strictly controlled throughout production.
At Chenfan Electric, transformer core production is controlled to maintain:
- Burr height below 0.02 mm
- Stable cutting accuracy
- Consistent lamination dimensions
- Controlled edge quality
This is especially important for medium and large transformer cores, where small manufacturing deviations can accumulate across thousands of laminations.
Stacking Factor Influences Core Dimensions
The stacking factor determines how effectively the CRGO laminations occupy the designed core section.
A lower stacking factor can result in:
- Larger actual core dimensions
- Reduced effective magnetic cross-section
- Higher magnetic flux density
- Possible increase in no-load loss
A high-quality CRGO transformer core should maintain a stable stacking factor throughout the entire assembly.
Chenfan Electric controls the stacking factor above 97%, helping maintain dimensional consistency and predictable magnetic performance.
Step-Lap Accuracy Is Critical
Modern transformer cores commonly use step-lap joints to reduce magnetic flux disturbance around the joint area.
However, the benefit of step-lap design depends heavily on manufacturing accuracy.
Incorrect step length, uneven lamination positioning or poor joint alignment can increase local magnetic resistance.
A precision step-lap transformer core requires accurate control of:
- Lamination length
- Step position
- Joint overlap
- Stacking sequence
- Core alignment
The cutting system must reproduce these dimensions consistently across every lamination.
Core Assembly Also Affects No-Load Loss
Core loss is not determined only by the CRGO material.
Mechanical stress introduced during stacking, handling, clamping or transportation can change the magnetic properties of electrical steel.
Improper assembly may cause local deformation, excessive clamping stress, joint misalignment or uneven core structure.
These factors can contribute to higher excitation current and no-load loss.
A professional transformer core supplier must therefore control both lamination manufacturing and final core assembly.
Material Selection Must Match the Transformer Design
Different transformer designs require different CRGO specifications.
Factors such as operating flux density, frequency, transformer capacity, core window dimensions, target no-load loss and efficiency requirements all influence material selection.
Using a higher-grade CRGO does not automatically guarantee the best technical or economic result.
The correct approach is to balance material performance, transformer design and manufacturing accuracy.
Complete Transformer Core Manufacturing
Chenfan Electric manufactures precision transformer cores for oil-immersed and dry-type transformers.
Production capabilities include:
- CRGO transformer core cutting
- Step-lap lamination
- Core stacking
- Complete assembled transformer cores
- Large transformer core manufacturing
- Customized production according to customer drawings
Core manufacturing is controlled according to customer dimensions and technical requirements.
For transformer manufacturers, receiving a fully assembled and dimensionally controlled core can reduce internal production workload and simplify transformer assembly.
Why Manufacturing Precision Matters
A transformer core may contain thousands of individual laminations.
A deviation that appears insignificant on one sheet can become a serious dimensional or magnetic issue after complete stacking.
This is why the difference between an ordinary supplier and a professional transformer core manufacturer is often found in process control.
CRGO grade matters.
But cutting precision, burr control, stacking factor, step-lap accuracy and assembly quality determine how that material performs inside the finished transformer.