Bs En/iec 60228 Link

The standard enforces resistance limits, not physical dimensions. A conductor with slightly fewer but purer copper strands can still comply, as long as its resistance is within limits.

Note: This class is largely obsolete or merged into Class 5 within modern revisions. Class 4: Flexible Conductors bs en/iec 60228

Note: Similar to Class 3, modern applications primarily reference Class 5 and Class 6 for flexible needs. Class 5: Flexible Conductors Composed of numerous thin wires strands. Designed for mobile equipment or tight spaces. High resistance to mechanical fatigue from bending. Frequently utilized in appliance cords and panel wiring. Class 6: Highly Flexible Conductors Constructed with the thinnest wire strands. Offers the maximum degree of flexibility. Built to endure continuous motion and vibration. The standard enforces resistance limits