Understanding of wires and cables flexibility

Understanding of wires and cables flexibility.

- What’s a wire flexibility class?

Electric conductor – the main element of a cable or wire structure. Electric current passes exactly through the electric conductor , transmitting electrical energy from a source to a consumer.

Electric conductor comes in two basic varieties: solid and stranded wire.

Stranded wire is more flexible than solid wire of the same total cross-sectional area.

- How to define the class of wire flexibility?

Based on the flexibility, depending on how many wires are in the core, there is a classification of wires into 6 classes of flexibility. As the wire class increases, the flexibility of a cable product based on it increases respectively. The higher the flexibility class, the more flexible cable products.

According to the standard there are 6 classes of electric conductor flexibility:

Wire flexibility class		Wire cross-section (mm2)		2,5	4	6	10	16	25	35	50	70	95	120	150	185	240
	Class 1	Copper/ aluminum wire	Nominal diameter (mm)	1,8	2,3	2,8	3,6	4,5	5,7	6,6	8	9,42	11	12,3	13,7	15,2	17,3
	Class 1	Copper/ aluminum wire	Number of cords in a wire	1	1	1	1	1	1	1	1	1	1	1	1	1 (35)	1 (35)
	Class 2	Copper/ aluminum wire	Nominal diameter (mm)	2	2,6	3,1	4,1	5,1	6,4	7,56	8,9	10,7	12,6	14,2	15,8	17,64	20,25
	Class 2	Copper/ aluminum wire	Number of cords in a wire	7	7	7	7	7	6	6	6	12	15	18	18	30	30
	Class 3	Copper wire	Nominal diameter (mm)	2,1	2,6	3,2	4	5,2	6,8	7,65	9,41	10,7	12,5	14,4	16	17,6	-
	Class 3	Copper wire	Number of cords in a wire	7	7	19	19	19	19	19	27	37	37	61	61	91	-
	Class 4	Copper wire	Nominal diameter (mm)	212	2,7	3,2	4,5	5,8	7,2	8,89	11,5	10,2	14,8	17	18,7	22,61	24,03
	Class 4	Copper wire	Number of cords in a wire	20	20	30	49	49	49	98	144	189	189	266	266	330	420
	Class 5	Copper wire	Nominal diameter (mm)	2,1	3	3,7	5,3	6	7,8	9,04	10,8	12,8	14,5	16,8	19,7	21,53	23,45
	Class 5	Copper wire	Number of cords in a wire	50	56	84	80	224	196	189	266	266	361	608	756	925	1221
	Class 6	Copper wire	Nominal diameter (mm)	2,4	3,1	3,7	5,1	6,2	788	9,84	11,4	12,9	14,7	17,1	18,9	20,37	23,72
	Class 6	Copper wire	Number of cords in a wire	140	228	189	324	513	783	1107	402	999	1332	1702	2109	2590	3360

Visual demonstration of the flexibility classification:

Wires of classes 1 and 2 are intended for cable products of fixed installation. Wires of classes 3, 4, 5 and 6 are designed for flexible cable products, but they can also be used for cable products of fixed installation.