6J40 Constantan Copper-Nickel Alloy The Optimal Choice for Stable Electrical Properties
A constant alloy is a type of metal alloy designed to maintain stable and consistent properties, particularly electrical resistance, over a wide range of temperatures. The most well-known constant alloy is Constantan, a copper-nickel alloy that is widely used in temperature sensors (thermocouples), resistors, and heating elements due to its stable electrical and thermal characteristics.
Constant alloys, like 6J40, are valued for their reliable and consistent performance in a wide range of applications. Their ability to maintain stable electrical resistance and durability under varying environmental conditions makes them essential in industries like electronics, manufacturing, and scientific instrumentation.
Chemical composition
Name | Code | Main Composition(%) | Density | |||
Cu | Mn | Ni | Cr | g/mm2 | ||
Constantan | 6J40 | Bal. | 1~2 | 39~41 | -- | 8.9 |
Properties
Name | Code | Resistivity(20℃)(μΩm) | Temp.Coeff.Of Resistance (20℃)(α×10-6/℃) | (0~100℃) Thermal EMF vs. Copper (μv/℃) | Max. Working Temp. (℃) | Elongation(%) | Tensile Strength(N/mm2) |
Constantan | 6J40 | 0.48±0.03 | -40~+40 | 45 | ≤500 | ≥15 | ≥390 |
Diameter and Tolerance
Diameter | 0.02~0.028 | 0.032~0.10 | 0.112~0.28 | 0.315~0.50 | 0.56~1.0 | 1.06~1.60 | 1.70~2.12 | 2.24~3.00 | 3.15~4.50 |
Tolerance | ±0.002 | ±0.003 | ±0.005 | ±0.010 | ±0.015 | ±0.020 | ±0.025 | ±0.030 | ±0.035 |
Some key features of 6J40 include:
Applications:
Constantan (6J40) Technical data of wires
Dia(m) | Cross-sectional area(m²) | Weight/m (g/m) | Resistance/m at 20℃(Ω/m) | Dia(m) | Cross-sectional area(m²) | Weight/m (g/m) | Resistance/m at 20℃(Ω/m) |
0.020 | 0.000314 | 0.00279 | 1375-1681 | 0.224 | 0.03941 | 0.350 | 11.4-12.9 |
0.022 | 0.000318 | 0.00337 | 1136-1389 | 0.250 | 0.04909 | 0.436 | 9.19-10.37 |
0.025 | 0.000491 | 0.00434 | 880-1076 | 0.280 | 0.06158 | 0.5468 | 7.33-8.26 |
0.028 | 0.000616 | 0.00547 | 702-857 | 0.315 | 0.07793 | 0.6920 | 5.85-6.47 |
0.032 | 0.000804 | 0.00714 | 549-645 | 0.355 | 0.09898 | 0.8789 | 4.61-5.09 |
0.036 | 0.001018 | 0.00904 | 434-509 | 0.400 | 0.12570 | 1.116 | 3.63-4.01 |
0.040 | 0.001257 | 0.01116 | 351-413 | 0.450 | 0.15900 | 1.412 | 2.87-3.17 |
0.045 | 0.001509 | 0.01412 | 278-326 | 0.500 | 0.19630 | 1.744 | 2.32-2.57 |
0.050 | 0.001963 | 0.01744 | 225-264 | 0.560 | 0.24630 | 2.19 | 1.87-2.03 |
0.056 | 0.002463 | 0.02187 | 179-210 | 0.630 | 0.31170 | 2.77 | 1.48-1.60 |
0.063 | 0.003117 | 0.02768 | 142-166 | 0.710 | 0.39590 | 3.52 | 1.16-1.26 |
0.071 | 0.003959 | 0.03516 | 112-131 | 0.750 | 0.44180 | 3.92 | 1.04-1.13 |
0.080 | 0.005027 | 0.04464 | 87.9-103.1 | 0.800 | 0.50270 | 4.46 | 0.917-0.993 |
0.090 | 0.006362 | 0.05650 | 69.4-81.5 | 0.850 | 0.56740 | 5.04 | 0.812-0.880 |
0.100 | 0.007854 | 0.06970 | 56.2-66.0 | 0.900 | 0.63620 | 5.65 | 0.724-0.785 |
0.112 | 0.009852 | 0.08749 | 45.3-52.1 | 0.950 | 0.70880 | 6.29 | 0.650-0.704 |
0.125 | 0.012270 | 0.10900 | 36.4-41.9 | 1.000 | 0.78540 | 6.97 | 0.587-0.636 |
0.140 | 0.015390 | 0.13670 | 29.0-33.4 | 1.060 | 0.88250 | 7.84 | 0.522-0.566 |
0.150 | 0.017670 | 0.15690 | 25.3-29.1 | 1.120 | 0.98520 | 8.75 | 0.468-0.507 |
0.160 | 0.020110 | 0.17850 | 22.2-25.5 | 1.180 | 1.09400 | 9.71 | 0.421-0.456 |
0.170 | 0.022700 | 0.20160 | 19.7-22.6 | 1.250 | 1.22700 | 10.9 | 0.375-0.407 |
0.180 | 0.025450 | 0.22600 | 17.5-20.2 | 1.320 | 1.36800 | 12.15 | 0.337-0.365 |
0.190 | 0.028350 | 0.25200 | 15.7-18.1 | 1.400 | 1.53900 | 13.67 | 0.299-0.324 |
0.200 | 0.031420 | 0.27900 | 14.4-16.2 | 1.500 | 1.76700 | 15.69 | 0.261-0.282 |
0.212 | 0.035300 | 0.31350 | 12.8-14.4 | 1.600 | 2.01100 | 17.86 | 0.229-0.248 |
Constantan strip resistance value (Ω/m)
Width Thickness |
6.3 | 8.0 | 10.0 | 12.5 | 16.0 | 20.0 | 25.0 | 31.5 | 40.0 |
0.180 | 0.150 | ||||||||
0.200 | 0.405 | ||||||||
0.224 | 0.362 | 0.2850 | |||||||
0.250 | 0.324 | 0.2550 | 0.196 | ||||||
0.280 | 0.289 | 0.2280 | 0.175 | ||||||
0.315 | 0.257 | 0.2030 | 0.155 | 0.124 | |||||
0.355 | 0.228 | 0.1800 | 0.138 | 0.110 | |||||
0.400 | 0.203 | 0.1600 | 0.122 | 0.980 | 0.0765 | ||||
0.450 | 0.180 | 0.1420 | 0.109 | 0.0871 | 0.0680 | 0.0544 | 0.0435 | ||
0.500 | 0.162 | 0.1280 | 0.098 | 0.0784 | 0.0612 | 0.0490 | 0.0392 | ||
0.560 | 0.145 | 0.1140 | 0.0875 | 0.0700 | 0.0547 | 0.0437 | 0.0350 | ||
0.630 | 0.129 | 0.1010 | 0.0777 | 0.0622 | 0.0486 | 0.0389 | 0.0311 | ||
0.710 | 0.114 | 0.0900 | 0.0690 | 0.0552 | 0.0431 | 0.0345 | 0.0276 | ||
0.800 | 0.101 | 0.0800 | 0.0612 | 0.0490 | 0.0383 | 0.0306 | 0.0245 | 0.0194 | 0.0153 |
0.900 | 0.090 | 0.0710 | 0.0544 | 0.0435 | 0.0340 | 0.0272 | 0.0218 | 0.0173 | 0.0136 |
1.000 | 0.081 | 0.0640 | 0.0490 | 0.0392 | 0.0306 | 0.0245 | 0.0196 | 0.0155 | 0.0122 |
1.120 | 0.072 | 0.0570 | 0.0437 | 0.0350 | 0.0273 | 0.0219 | 0.0175 | 0.0139 | 0.0109 |
1.250 | 0.065 | 0.0510 | 0.0392 | 0.0313 | 0.0245 | 0.0196 | 0.0157 | 0.0124 | 0.0098 |
1.400 | 0.058 | 0.0460 | 0.0350 | 0.0280 | 0.0219 | 0.0175 | 0.0140 | 0.0111 | 0.0088 |
1.600 | 0.051 | 0.0400 | 0.0306 | 0.0245 | 0.0191 | 0.0153 | 0.0122 | 0.0097 | 0.0077 |
1.800 | 0.045 | 0.0350 | 0.0272 | 0.0218 | 0.0170 | 0.0136 | 0.0109 | 0.0086 | 0.00680 |
2.000 | 0.041 | 0.0320 | 0.0245 | 0.0196 | 0.0153 | 0.0122 | 0.0098 | 0.0078 | 0.0061 |
Constantan&Manganin wire table
Dia.(mm) | Sectional area nominal value(mm2) | Resistance per meter (Ω/m) | ||||||||
6J12X | 6J8X | 6J13X | 6J40X | |||||||
Nominal value(mm) | Tolerance | Nominal value (Ω/m) | Tolerance | Nominal value (Ω/m) | Tolerance | Nominal value (Ω/m) | Tolerance | Nominal value (Ω/m) | Tolerance | |
0.020 | ±0.002 | 0.000314 | 1496 | ±10% | 1528 | ±10% | ||||
0.022 | 0.000380 | 1236 | 1263 | |||||||
0.025 | 0.000491 | 957 | 978 | |||||||
0.028 | 0.000616 | 763 | 780 | |||||||
0.032 | ±0.003 | 0.000804 | 584 | ±8% | ±8% | ±8% | 597 | ±8% | ||
0.036 | 0.001018 | 462 | 472 | |||||||
0.040 | 0.001257 | 374 | 382 | |||||||
0.045 | 0.001590 | 296 | 302 | |||||||
0.050 | 0.001963 | 239 | 244 | |||||||
0.056 | 0.002463 | 191 | 195 | |||||||
0.063 | 0.003117 | 151 | 154 | |||||||
0.071 | 0.003959 | 119 | 121 | |||||||
0.080 | 0.005027 | 93.5 | 69.6 | 87.5 | 95.5 | |||||
0.090 | 0.006362 | 73.9 | 55.0 | 69.2 | 75.5 | |||||
0.100 | 0.007854 | 59.8 | 44.6 | 56.0 | 61.1 | |||||
0.112 | ±0.005 | 0.009852 | 47.7 | ±7% | 35.5 | ±7% | 44.7 | ±7% | 48.7 | ±7% |
0.125 | 0.01227 | 38.3 | 28.5 | 35.9 | 39.1 | |||||
0.140 | 0.01539 | 30.5 | 22.7 | 28.6 | 31.2 | |||||
0.160 | 0.02011 | 23.4 | 17.4 | 21.9 | 23.9 | |||||
0.180 | 0.02545 | 18.5 | 13.8 | 17.3 | 18.9 | |||||
0.200 | ±0.005 | 0.03142 | 15.0 | ±6% | 11.1 | ±6% | 14.0 | ±6% | 15.3 | ±6% |
0.224 | 0.03941 | 11.9 | 8.88 | 11.2 | 12.2 | |||||
0.250 | 0.04909 | 9.57 | 7.13 | 8.96 | 9.78 | |||||
0.280 | 0.06158 | 7.63 | 5.68 | 7.15 | 7.80 | |||||
0.315 | ±0.010 | 0.007793 | 6.03 | ±5% | 4.49 | ±5% | 5.65 | ±5% | 6.16 | ±5% |
0.355 | 0.09898 | 4.75 | 3.54 | 4.45 | 4.85 | |||||
0.400 | 0.1257 | 3.74 | 2.79 | 3.50 | 3.82 | |||||
0.450 | 0.1590 | 2.96 | 2.20 | 2.77 | 3.02 | |||||
0.500 | ±0.015 | 0.1963 | 2.39 | ±4% | 1.78 | ±4% | 2.24 | ±4% | 2.44 | ±4% |
0.560 | 0.2463 | 1.91 | 1.42 | 1.79 | 1.95 | |||||
0.630 | 0.3117 | 1.51 | 1.12 | 1.41 | 1.51 | |||||
0.710 | 0.3959 | 1.19 | 0.884 | 1.11 | 1.21 | |||||
0.750 | 0.4418 | 1.06 | 0.792 | 1.00 | 1.09 | |||||
0.800 | 0.5027 | 0.935 | 0.696 | 0.875 | 0.955 | |||||
0.850 | 0.5674 | 0.828 | 0.617 | 0.775 | 0.846 | |||||
0.900 | 0.6362 | 0.739 | 0.550 | 0.692 | 0.755 | |||||
0.950 | 0.7088 | 0.663 | 0.494 | 0.621 | 0.677 | |||||
1.000 | 0.7854 | 0.598 | 0.446 | 0.560 | 0.611 | |||||
1.060 | ±0.020 | 0.8852 | 0.533 | ±4% | 0.397 | ±4% | 0.499 | ±4% | 0.544 | ±4% |
1.120 | 0.9852 | 0.477 | 0.355 | 0.447 | 0.487 | |||||
1.180 | 1.094 | 0.430 | 0.320 | 0.402 | 0.439 | |||||
1.250 | 1.227 | 0.383 | 0.285 | 0.359 | 0.391 | |||||
1.320 | 1.368 | 0.343 | 0.256 | 0.322 | 0.351 | |||||
1.400 | 1.539 | 0.305 | 0.227 | 0.286 | 0.312 | |||||
1.500 | 1.767 | 0.266 | 0.198 | 0.249 | 0.272 | |||||
1.600 | 2.011 | 0.234 | 0.174 | 0.219 | 0.239 | |||||
1.700 | ±0.025 | 2.270 | 0.207 | ±4% | 0.154 | ±4% | 0.194 | ±4% | 0.211 | ±4% |
1.800 | 2.545 | 0.185 | 0.138 | 0.173 | 0.189 | |||||
1.900 | 2.835 | 0.166 | 0.123 | 0.155 | 0.169 | |||||
2.000 | 3.142 | 0.15 | 0.111 | 0.140 | 0.153 | |||||
2.120 | 3.530 | 0.133 | 0.0992 | 0.125 | 0.136 | |||||
2.240 | ±0.030 | 3.941 | 0.119 | ±4% | 0.0888 | ±4% | 0.112 | ±4% | 0.122 | ±4% |
2.360 | 4.374 | 0.107 | 0.0800 | 0.101 | 0.110 | |||||
2.500 | 4.909 | 0.0957 | 0.0713 | 0.0896 | 0.0978 | |||||
2.650 | 5.515 | 0.0852 | 0.0635 | 0.0798 | 0.0870 | |||||
2.800 | 6.158 | 0.0763 | 0.0568 | 0.0715 | 0.0780 | |||||
3.000 | 7.069 | 0.0665 | 0.0495 | 0.0622 | 0.0679 | |||||
3.150 | ±0.035 | 7.793 | 0.0603 | ±4% | 0.0449 | ±4% | 0.0565 | ±4% | 0.0616 | ±4% |
3.350 | 8.814 | 0.0533 | 0.0397 | 0.0499 | 0.0545 | |||||
3.550 | 9.898 | 0.0475 | 0.0354 | 0.0445 | 0.0485 | |||||
3.750 | 11.04 | 0.0426 | 0.0317 | 0.0398 | 0.0435 | |||||
4.000 | 12.57 | 0.0374 | 0.0279 | 0.0350 | 0.0382 | |||||
4.250 | 14.19 | 0.0331 | 0.0247 | 0.0310 | 0.0338 | |||||
4.500 | 15.90 | 0.0296 | 0.0220 | 0.0277 | 0.0302 | |||||
4.750 | ±0.040 | 17.72 | 0.0265 | ±4% | 0.0198 | ±4% | 0.0248 | ±4% | 0.0271 | ±4% |
5.000 | 19.63 | 0.0239 | 0.0178 | 0.0224 | 0.0244 | |||||
5.300 | ±0.050 | 22.06 | 0.0213 | ±4% | 0.0159 | ±4% | 0.0199 | ±4% | 0.0218 | ±4% |
5.600 | 24.63 | 0.0191 | 0.0142 | 0.0179 | 0.0195 | |||||
6.000 | ±0.060 | 28.27 | 0.0166 | ±4% | 0.0124 | ±4% | 0.0156 | ±4% | 0.017 | ±4% |
6.300 | 31.17 | 0.0151 | 0.0112 | 0.0141 | 0.0154 |