IEC 62420:2008规定了同心层绞合架空电导体的电气和机械特性，所述同心层绞合架空电导体包含一个或多个由以下任一金属线的组合制成的自支撑铝或铝合金层: -根据IEC 60889的手工拉制铝，指定为A1； -根据IEC 60104的A型或B型铝合金，指定为A2或A3； -根据IEC 62004的耐热铝合金，指定为AT1、AT2、AT3或AT4； -符合IEC 60888的常规强度钢，指定为S1A或S1B； -符合IEC 60888的高强度钢，指定为S2A或S2B； -符合IEC 60888的超高强度钢，指定为S3A； -符合IEC 61232的铝包钢，指定为20SA、27SA、30SA或40SA。

IEC 62420:2008 specifies the electrical and mechanical characteristics of concentric lay stranded overhead electrical conductors, containing one or more self-supporting alumimium or aluminium alloy layer(s) made of combination of any of the following metal wires:
- Hand drawn aluminium as per IEC 60889, designated A1;
- aluminium alloy type A or B as per IEC 60104, designated A2 or A3;
- thermal resistant aluminium alloy as per IEC 62004, designated AT1, AT2, AT3, or AT4;
- regular strength steel as per IEC 60888, designated S1A or S1B;
- high strength steel as per IEC 60888, designated S2A or S2B;
- extra-high strength steel as per IEC 60888, designated S3A;
- aluminium-clad steel as per IEC 61232, designated 20SA, 27SA, 30SA or 40SA.