Class 240 Polyimide Square Copper Magnet Wire

Class 240 Polyimide Enameled Square Copper Magnet Wire is capable of long-term operation in environments up to 240°C without degradation. In some extreme cases, it can even tolerate short-term or transient exposure to temperatures ranging from 300°C to 450°C.

Insulating Material

The coating is based on aromatic polyimide resins

The insulation layer consists of one or two layers of polyimide film tape, which is coated on one or both sides with a suitable adhesive, such as fluorinated ethylene propylene. After winding, the film tape can be sintered to form a continuous, bonded sheath. 

Class 240 Polyimide Square Copper Magnet Wire is mainly used in electrical equipment that requires long-term exposure to high temperatures or special environmental conditions.

Transformers

Motors

Other Electromagnetic Coils: For devices like relays, sensors, and various induction devices, etc.

Special Environments: In settings with high temperatures, high humidity, or chemical corrosion—such as industrial automation and chemical processing equipment

Table 1 Dimensions

Insulation materials	Polyimide
Thermal Class	240
Bare Wire Dimensions	AWG 1 – AWG 14
Standard	MW 20-C

Heavy and Quad Film-Insulated Square Magnet Wire Increase in Dimensions Due to Film Coating

Square AWGSize	Bare Wire Dimensions			Radii (±25%)Nominal	Heavy		Quadruple
					Minimum Increase	Maximum Overall	Minimum Increase	Maximum Overall
	Minimum	Nominal	Maximum
1	7.275	7.348	7.422	1.00	0.080	7.549	0.127	7.600
2	6.477	6.543	6.609	1.00	0.080	6.736	0.127	6.787
3	5.768	5.827	5.885	1.00	0.080	6.012	0.127	6.063
4	5.138	5.189	5.240	1.00	0.080	5.367	0.127	5.418
5	4.575	4.620	4.666	1.00	0.080	4.793	0.127	4.844
6	4.074	4.115	4.155	0.80	0.080	4.282	0.127	4.333
7	3.630	3.665	3.701	0.80	0.080	3.828	0.127	3.879
8	3.231	3.264	3.297	0.80	0.080	3.424	0.127	3.475
9	2.878	2.906	2.934	0.67	0.080	3.061	0.127	3.112
10	2.563	2.588	2.614	0.67	0.080	2.741	0.127	2.791
11	2.278	2.304	2.329	0.50	0.080	2.456	0.127	2.507
12	2.027	2.052	2.078	0.50	0.080	2.205	0.127	2.256
13	1.803	1.829	1.854	0.40	0.080	1.981	0.127	2.032
14	1.603	1.628	1.654	0.40	0.080	1.781	0.127	1.831

Table 2 Properties

Adherence and flexibility	No cracks visible in the film coating
Elongation	MW Specification:18, 20, 36, 38, 64, 84 T ≥ 0.049: 32 T < 0.049:30
Heat shock	No cracks in the film coating after 15% elongation followed by conditioning at 280°C ±3ºC
Springback	Not greater than 5°
Dielectric breakdown	500V – 1500V
Dissipation Factor	Not greater than 0.60%

Table 3 Periodic conformance tests

Solubility	Specimens immersed in xylene and 50/50 xylene/butyl Cellosolve shall not soften sufficiently to expose the bare conductor
Dielectric breakdown rated temperature	Average not less than 75% of the value required at room temperature
Thermoplastic flow	Median not less than 450°C, when tested on MW 16-C Heavy build