Toroidal Cores
Manufacture
The manufacture of Strip Wound Cores is a specialized process that requires a high degree of precision. They are manufactured from selected coils of CRGO Electrical Steel, to attain closely controlled electro-magnetic characteristics and dimensional accuracy.
Cores are wound on the Core Winding Machine after Slitting is done as per the required shape. The Winding Machine automatically stops when the prescribed dimensions are reached. The start and finish ends are firmly spot-welded. After winding, the Cores are stress-relief annealed to restore the magnetic properties. The Cores are bonded where necessary, to provide increased firmness. All Cores are spray-painted and tested for magnetic properties.
Testing
Strip Wound Cores, unlike Strip Laminations, constitute a complete product, and every Core must meet the specified performance requirement. Consequently, quality control in the manufacture of Wound Cores is critically important at every stage of process.
Dimensional Tolerances
The coils of CRGO Steel are carefully selected after lab tests to ensure that the optimal grade of steel is used. Strict checks are made at every stage — from winding to the final stage of spray-painting, to ensure that the finished product is of a superior quality.
Moreover, each Core is subject to inspection and electrical tests to ensure that the customer’s specified performance requirement is met with.
| Inside Diameter (d) | Outside Diameter (d) | Height (h) | ||||||
|---|---|---|---|---|---|---|---|---|
| Over | Upto | Tol. | Over | Upto | Tol. | Over | Upto | Tol. |
| 30 | 100 | + 1.2 | 30 | 100 | + 1.5 | 0 | 150 | + 1.0-0 |
| 100 | 150 | + 1.5 | 100 | 200 | + 2.0 | 150 | 200 | +1.2-0 |
| 150 | 200 | + 2.0 | 200 | 400 | + 3.0 | 200 | 500 | +2.0-0 |
| 200 | 400 | + 3.0 | 400 | 800 | + 4.0 | 500 | – | +3.0-0 |
| 400 | 700 | + 4.0 | – | – | – | – | – | – |