1. Let's look at the packaging. The wires in the national standard are often made well and neatly, and they have a sense of quality when held by hand.

2. It's time to open the package and have a look at the wires inside. The wire thickness (insulation thickness) of 1.5-6 square meters required by the national standard is .7mm, if it is too thick, it is not the standard, and the inner core is definitely not enough. You can pull the wire skin hard, and the one that is not easy to tear is generally the national standard.

3. set it on fire, and those that go out within 5s after leaving will be the national standard line with certain flame retardant function.

4. Looking at the inner core, the higher the brightness of the material (copper) of the inner core, the better the copper is, and the brightness is even, shiny and has no layering. The national standard requires that the inner core must use oxygen-free copper. Non-standard items such as black rod copper may have hidden dangers of accidents.

5. The thickness of the inner core has certain requirements, but it is not very strict. But it won't be a lot wrong, just a little bit, which is generally invisible to the eye.

6, length, the country does not force you to beat rice, but many manufacturers also beat rice, which is not necessarily the national standard, but the general national standard generally does not beat rice. Non-standard rice beating is just a means.

7. According to the national regulations, wires must be marked with a certain logo, and the same logo will be printed when the maximum size is not more than 5mm, with the product trademark, manufacturer name, implementation standard, etc.

Baidu Encyclopedia-Wire and Cable.