General Engineering Data

GENERAL ENGINEERING DATA

Bare, Film and Fabric Insulated Magnet Wire

Tolerance on Nominal Diameter of Conductor
Comparison of Wire Gauges
Dimensions of Enamelled Wires (R20)
Formula for Calculating Weights and Resistances @ 20°c
Physical Constants @ 20°c
Factors for Converting Copper Resistance to 20°c
Variations in Conductor Resistance Due to Diameter Tolerance
Recommended Winding Tensions
Insulation Classes

TOLERANCE ON NOMINAL DIAMETER OF CONDUCTOR

Nominal diameter, mm	Tolerance +-, mm
0.071	0.003
0.080	0.003
0.090	0.003
0.100	0.003
0.112	0.003
0.125	0.003
0.140	0.003
0.160	0.003
0.180	0.003
0.200	0.003
0.224	0.003
0.250	0.004
0.280	0.004
0.315	0.004
0.355	0.004
0.400	0.005
0.450	0.005
0.500	0.005
0.560	0.006
0.630	0.006
0.710	0.007
0.750	0.008
0.800	0.008
0.850	0.009
0.900	0.009
0.950	0.010
1.000	0.010
1.060	0.011
1.120	0.011
1.180	0.013

Nominal diameter, mm	Tolerance +-, mm
1.250	0.013
1.320	0.014
1.400	0.014
1.500	0.016
1.600	0.016
1.700	0.018
1.800	0.018
1.900	0.020
2.000	0.020
2.120	0.022
2.240	0.022
2.360	0.025
2.500	0.025
2.650	0.028
2.800	0.028
3.000	0.032
3.150	0.032
3.350	0.036
3.550	0.036
3.750	0.040
4.000	0.040
4.250	0.050
4.500	0.050
4.750	0.050
5.000	0.050

Note: For intermediate sizes use tolerance applicable to the next large nominal diameter listed.

COMPARISON OF WIRE GAUGES

Standard Metric Sizes with SWG and AWG Sizes

Metric Standard	Nearest SWG Gauge (mm)	Nearest AWG Gauge (mm)
5.00	6(4.877)	4(5.189)
4.75
4.50	7(4.470)	5(4.620)
4.25
4.00	8(4.064)	6(4.115)
3.75
3.55	9(3.658)	7(3.665)
3.35
3.15	10(3.25)	8(3.26)
3.00	11(2.95)	9(2.91)
2.80
2.65	12(2.64)	10(2.59)
2.50
2.36	13(2.34)	11(2.30)
2.24
2.12
2.00	14(2.03)	12(2.05)
1.90
1.80	15(1.83)	13(1.83)
1.70
1.60	16(1.63)	14(1.63)
1.50
1.40	17(1.42)	15(1.45)
1.32
1.25	18(1.22)
1.18
1.12		17(1.15)
1.06
1.00	19(1.02)	18(1.02)
0.95
0.090	20(0.91)	19(0.91)
0.85
0.80	21(0.81)	20(0.81)
0.75
0.71	22(0.71)	21(0.72)
0.67
0.36		22(0.64)
0.60	23(061)

Metric Standard	Nearest SWG Gauge (mm)	Nearest AWG Gauge (mm)
0.560	24(0.56)	23(0.57)
0.530
0.500	25(0.51)	24(0.51)
0.475
0.450	26(0.46)	25(0.45)
0.425	27(0.42)
0.400		26(0.40)
0.375	28(0.38)
0.355	29(0.35)	27(0.36)
0.335
0.315	30(0.31)	28(0.32)
0.300	31((0.29)	29(0.28)
0.280	32(0.27)
0.265
0.250	33(0.25)	30(0.25)
0.236	34(0.23)	31(0.23)
0.224
0.212	35(0.21)
0.200		32(0.20)
0.190	36(0.19)
0180		33(0.18)
0.170	37(0.17)
0.160		34(0.16)
0.150	38(0.15)
0.140		35(0.14)
0.132	39(0.13)	36(0.13)
0.125	40(0.12)	37(0.11)
0.112	41(0.11)	37(0.11)
0.100	42(0.10)	38(0.10)
0.090	43(0.09)	39(0.09)
0.080	44(0.08)	40(0.08)
0.071	45(0.07)	41(0.07)
0.063
0.060	46(0.06)	42(0.06)
0.056
0.050	47(0.05)	43(0.05)

TABLE 1 - DIMENSIONS OF
ENAMELLED WIRES (R20)

Nominal coduc- tor diameter mm	Conductor tolerance +/- mm	Minimum increase due to the insulation mm			Maximum overall diameter mm
Nominal coduc- tor diameter mm	Conductor tolerance +/- mm	Grade 1	Grade 2	Grade 3	Grade 1	Grade 2	Grade 3
0.018					0.022	0.024
0.020					0.024	0.027
0.022			0.027	0.030
0.025					0.031	0.034
0.028					0.034	0.038

0.032					0.039	0.043
0.036					0.044	0.049
0.040					0.049	0.054
0.045					0.055	0.061
0.050					0.060	0.066

0.056					0.067	0.074
0.063					0.076	0.083
0.071	0.003	0.007	0.012	0.018	0.084	0.091	0.097
0.080	0.003	0.007	0.014	0.020	0.094	0.101	0.108
0.090	0.003	0.008	0.015	0.022	0.105	0.113	0.120

0.100	0.003	0.008	0.016	0.023	0.117	0.125	0.132
0.112	0.003	0.009	0.017	0.026	0.130	0.139	0.147
0.125	0.003	0.010	0.019	0.028	0.144	0.154	0.163
0.140	0.003	0.011	0.021	0.030	0.160	0.171	0.181
0.160	0.003	0.012	0.023	0.033	0.182	0.194	0.205

0.180	0.003	0.013	0.025	0.036	0.204	0.217	0.229
0.200	0.003	0.014	0.027	0.039	0.226	0.239	0.252
0.224	0.003	0.015	0.029	0.043	0.252	0.266	0.280
0.250	0.004	0.017	0.032	0.048	0.281	0.297	0.312
0.280	0.004	0.018	0.033	0.050	0.312	0.329	0.345

0.315	0.004	0.019	0.035	0.053	0.349	0.367	0.384
0.355	0.004	0.020	0.038	0.057	0.392	0.411	0.428
0.400	0.005	0.021	0.040	0.060	0.439	0.459	0.478
0.450	0.005	0.022	0.042	0.064	0.491	0.513	0.533
0.500	0.005	0.024	0.045	0.067	0.544	0.566	0.587

0.560	0.006	0.025	0.047	0.071	0.606	0.630	0.653
0.630	0.006	0.027	0.050	0.075	0.679	0.704	0.728
0.710	0.007	0.028	0.053	0.080	0.762	0.789	0.814
0.800	0.008	0.030	0.056	0.085	0.855	0.884	0.911
0.900	0.009	0.032	0.060	0.090	0.959	0.989	1.018

1.000	0.010	0.034	0.063	0.095	1.062	1.094	1.124
1.120	0.011	0.034	0.065	0.098	1.184	1.217	1.248
1.250	0.013	0.035	0.067	0.100	1.316	1.349	1.381
1.400	0.014	0.036	0.069	0.103	1.468	1.502	1.535
1.600	0.016	0.038	0.071	0.107	1.670	1.706	1.740

1.800	0.018	0.039	0.073	0.110	1.872	1.909	1.944
2.000	0.020	0.040	0.075	0.113	2.074	2.112	2.148
2.240	0.022	0.041	0.077	0.116	2.316	2.355	2.392
2.500	0.025	0.042	0.079	0.119	2.578	2.618	2.656
2.800	0.028	0.043	0.081	0.123	2.880	2.922	2.961

3.150	0.032	0.045	0.084	0.127	3.233	3.276	3.316
3.550	0.036	0.046	0.086	0.130	3.635	3.679	3.721
4.000	0.040	0.047	0.089	0.134	4.088	4.133	4.176
4.500	0.045	0.049	0.092	0.138	4.591	4.637	4.681
5.00	0.050	0.050	0.094	0.142	5.093	5.141	5.186
NOTES National Committees may use minimum overall diameter requirements provided they are based on the minimum increases. The calculation is given in annex B. For intermediate nominal conductor diameters, the minimum increase figure corresponding to the next largest nominal conductor diameter shall be taken. The dimensions of intermediate nominal conductor diameters for R40 series are given in annex A.

FORMULA FOR CALCULATING WEIGHTS
AND RESISTANCES @ 20°C

FORMULA FOR CALCULATING WEIGHTS AND RESISTANCES@20°C
	COPPER
Weight kg/km	8.8897xa
Length: m/kg	112.5066 a
Resistance: ohm/km	17.2417 a
ohm/kg	1.93975 a²

a = nominal cross sectional area of wire in square millimeters

PHYSICAL CONSTANTS @ 20°C

PHYSICAL CONSTANTS @ 20°C
PROPERTY	ANNEALED COPPER
Volume electrical conductivity minimum percent I.A.C.S.	100.0
Density: kg/m³	8888.4
Weight resistivity: ohm-mm²/m	17.2417x10-³
Volume resistivity: micro-ohm-mm	17.2417
Temperature coefficient of resistance; ohm/°C	.00393
Specific heat; cal/gm/°C	.092
Coefficient of thermal conductivity cal/sec/cm²/cm/°C	.934
Coefficient of linear expansion/°C	.0000168

FACTORS FOR CONVERTING COPPER
RESISTANCE TO 20°C

FACTORS FOR CONVERTING COPPER RESISTANCE TO 20°C @100% CONDUCTIVITY (I.A.C.S)
°C	FACTOR	°C	FACTOR	°C	FACTOR	°C	FACTOR	°C	FACTOR
0	1.0853
1	1.0807	51	.8914	101	.7586	151	.6602	201	.5844
2	1.0761	52	.8883	102	.7563	152	.6585	202	.5830
3	1.0716	53	.8852	103	.7514	153	.6568	203	.5817
4	1.0671	54	.8821	104	.7518	154	.6551	204	.5804
5	1.0626	55	.8791	105	.7496	155	.6534	205	.5791
6	1.0582	56	.8761	106	.7474	156	.6517	206	.5778
7	1.0538	57	.8731	107	.7452	157	.6501	207	.5764
8	1.0495	58	.8701	108	.7431	158	.6484	208	.5751
9	1.0452	59	.8671	109	.7409	159	.6468	209	.5738
10	1.0409	60	.8642	110	.7388	160	.6451	210	.5726
11	1.0367	61	.8613	111	.7366	161	.6435	211	.5713
12	1.0325	62	.8583	112	.7345	162	.6419	212	.5700
13	1.0283	63	.8555	113	.7324	163	.6403	213	.5687
14	1.0241	64	.8526	114	.7303	164	.6386	214	.5674
15	1.0200	65	.8497	115	.7282	165	.6370	215	.5662
16	1.0160	66	.8469	116	.7261	166	.6355	216	.5649
17	1.0119	67	.8441	117	.7240	167	.6339	217	.5637
18	1.0079	68	.8413	118	.7220	168	.6323	218	.5624
19	1.0039	69	.8386	119	.7199	169	.6307	219	.5612
20	1.0000	70	.8358	120	.7179	170	.6292	220	.5600
21	.9961	71	.8331	121	.7159	171	.6276	221	.5587
22	.9922	72	.8303	122	.7139	172	.6261	222	.5575
23	.9883	73	.8276	123	.7119	173	.6245	223	.5563
24	.9845	74	.8250	124	.7099	174	.6230	224	.5551
25	.9807	75	.8223	125	.7079	175	.6215	225	.5539
26	.9770	76	.8196	126	.7060	176	.6200	226	.5527
27	.9732	77	.8170	127	.7040	177	.6185	227	.5515
28	.9695	78	.8144	128	.7021	178	.6170	228	.5503
29	.9658	79	.8118	129	.7001	179	.6155	229	.5491
30	.9622	80	.8092	130	.6982	180	.6140	230	.5479
31	.9586	81	.8067	131	.6963	181	.6125	231	.5467
32	.9550	82	.8041	132	.6944	182	.6110	232	.5456
33	.9514	83	.8016	133	.6925	183	.6096	233	.5444
34	.9479	84	.7991	134	.6906	184	.6081	234	.5479
35	.9443	85	.7966	135	.6888	185	.6067	235	.5421
36	.9409	86	.7941	136	.6869	186	.6052	233	.5444
37	.9374	87	.7916	137	.6851	187	.6038	237	.5398
38	.9339	88	.7891	138	.6832	188	.6024	238	.5386
39	.9305	89	.7867	139	.6814	189	.6009	239	.5375
40	.9271	90	.7843	140	.6796	190	.5995	240	.5364
41	.9238	91	.7819	141	.6778	191	.5981	241	.5352
42	.9240	92	.7795	142	.6760	192	.5967	242	.5341
43	.9171	93	.7771	143	.9742	193	.5953	243	.5341
44	.9138	94	.7747	144	.6724	194	.5939	244	.5319
45	.9106	95	.7724	154	.6706	195	5925	245	.5308
46	.9073	96	.7700	146	.6689	196	.5912	246	.5397
47	.9041	97	.7677	147	.6671	197	.5898	247	.5286
48	.9009	98	.7654	148	.6654	198	.5884	248	.5275
49	.8977	99	.7631	149	.6636	199	.5871	249	.5264
50	.8946	100	.7608	150	.6619	200	.5857	250	.5253

VARIATIONS IN CONDUCTOR RESISTANCE
DUE TO DIAMETER TOLERANCE

The resistance of a given length of wire is inversely proportional to its cross-sectional area, and thus for round wire the square of its diameter:

where	d	is the diameter in millimetres
	a	is the cross-sectional area in square millimetres

It is easily seen that the resistance will reach its maximum diameter.

The wire diameter corresponding to any resistance measurement is given by the following:

where r is the resistance in ohms/km

RECOMMENDED WINDING TENSIONS
COPPER

RECOMMENDED WINDING TENSIONS

SIZE Millimeters	COPPER (598 kg/cm²)
3.15	49.9 kg
3.00	39.5 kg
2.65	33.4 kg
2.36	24.9 kg
2.00	19.9 kg
1.80	15.6 kg
1.60	12.5 kg
1.40	9.99 kg
1.32	7.85 kg
1.12	6.26 kg
1.00	4.94 kg
0.90	3.89 kg
0.80	3.10 kg
0.71	2.46 kg
0.63	1.94 kg
0.56	1.54 kg
0.50	1.23 kg
0.45	.975 kg
0.40	.771 kg

SIZE Millimeters	COPPER (598 kg/cm²)
0.355	.621 kg
0.315	.485 kg
0.30	.385 kg
0.25	.303 kg
0.236	.240 kg
0.20	.194 kg
0.18	.152 kg
0.16	.120 kg
0.14	.095 kg
0.132	.0757 kg
0.112	.0612 kg
0.10	.0485 kg
0.09	.0368 kg
0.08	.0292 kg
0.071	.0237 kg
0.06	.0189 kg
0.056	.0147 kg
0.05	.0121 kg

INSULATION CLASSES

Insulating materials are classified according to IEC standards into insulating classes showing the corresponding maximum working temperatures that must not be exceeded at any point of the winding. The table below outlines the recognised insulation classifications.

Only mentioned are those insulating materials directly concerned with Transwire.


Class	Temperature °C	Insulating materials

Y	90	Paper not impregnated

A	105	Paper if impregnated

E	120	Polyvinyl Formel - Polyurethane enamels

B	130	Fibre-glass impregnated - Modified polyurethane enamels.

F	155	Fibre-glass impregnated in polyester and epoxy resins - Modified polyurethane enamels

H	180	Polyesterimide enamels - Fibre-glass impregnated in class H varnishes

C	200	NOMEX* Fibre-glass impregnated in silicon resins. Polyamide - imide enamels.

	220	KAPTON*

* Du Pont De Nemours & Co USA trade mark.