We specialise in the manufacture of Step-Lap transformer cores
from small distribution to large power cores.

Mitred cores built to your specific requirements

Ranging from 5kVA to 40MVA. Cores are mitred from specialised Grain Orientated Electrical Steel Strips. This is critical in order to meet the demand of low losses that Electrical Utilities demand.

Latest Technologies
We pride ourselves with keeping in touch with the latest materials and technologies.
Tested and Guaranteed
All material is tested before manufacture with our in-house Soken Iron loss tester.
Highest Quality
We deliver quality cores with quick turnaround times at fair prices.

Core Assembly

Mitred Laminations

Mitred Laminations

Mitre cores are manufactured as vertical or horizontal Step-Lap. Our preferred strip widths are from 40mm to 600mm in increments of 10mm.

As a standard, a 10.3mm hole is punched in the laminations for stacking accuracy. Available punch sizes are: 8, 10.3, 13, 18, 24 and 32mm diameter. We are able to punch holes in the Yokes and Limbs. Any other hole size available on request.

Available Core types:
  • Single phase shell type.
  • Single phase core type.
  • Three phase Evans design.
  • Three phase 5 limb.


We manufacture flat or round Yokes as well as oval or round Limbs as per customer requirements.

Our standard displacement for cores under 160kVA is10mm (5/5). For cores greater that 160kVA the standard displacement is 20mm (10/10). Cores can be supplied cut and stacked or cut and packed as per customer specification.

Testing Facilities

Our specialised mitred cores and Step-Lap cores are made from the best Grain Orientated Electrical Steels available. Each core is guaranteed and comes with a comprehensive test certificate showing actual no-load losses as well as dimensional specifications.

All material is tested before manufacture with our in-house Soken Iron loss tester.

These test results are compared to the mill test certificates to ensure quality and authenticity of material used.

Stock Holding

We keep a comprehensive range of raw material in stock to meet all requirements. The table below shows the grades of steel we supply with the guaranteed losses.


Grade Thickness Density Max Core Loss at 50Hz (W/kg) Min Induction 
at 800 A/m, T
      1.5T 1.7T  
23H85 0.23 7.65 0.57 0.80 1.91
23H90 0.23 7.65 0.66 0.90 1.91
MOH 0.27 7.65 0.76 1.05 1.90
M4 0.27 7.65 0.90 1.32 1.88
M5 0.30 7.65 0.97 1.39 1.88
M6 0.35 7.65 1.57 1.57 1.88

We supply specific core loss curves on request. Please note the final losses of the core will vary and typically losses will be higher in three phase and in single phase cores due to the stack factor and destruction factor of the core. Performance curves (W/kg) available on request.

Slitting Lines

MCT has its own slitting lines and can slit wide coil of 1.2m down to 40mm strip widths and 600mm down to 10mm strip widths.

Mitering Machines

We build mitred cores to customer specific requirements.

Core Clamps

We manufacture Core Clamps in-house to our customer specifications.
Please send us your drawings for quotation purposes.

Whatever your requirements, we can manufacture. CONTACT US