Why do some physical stores sell wires and cables cheaper than manufacturers?

According to our traditional thinking, this factory is mass produced and the price is absolutely cheap. In fact, there are two important reasons for making physical stores cheaper. First of all, the wires sold by physical stores may not be neat enough. For example, when a customer buys a 4 square decorative line, the actual decorative line may only be 3 square. Secondly, the wires sold in physical stores may lack meters. A 100 meter long wire may actually be only 90 meters long. Don't underestimate the lack of squares, which is actually very harmful. If the square is not enough, the resistance will not be reached, and the wire will heat up, which may cause a fire.

Because it is inconvenient to measure the meters of wires, customers tend to ignore them, which may increase unnecessary costs in the decoration process. The small editor teaches you a simple way to see if the wires you buy are not enough meters. First, cut a meter long wire, weigh it, and then multiply it by the number of meters you bought to see if it is inconsistent with the actual weight, so you can clearly know whether the wire you bought is enough.

The main raw material of electric wire is copper. 

Of course, the price ratio of copper is relatively large. Therefore, when purchasing wires, you must know whether the wires you buy are square. This is the key point of price. 

The following methods may be useful:

Strip the insulation of the cable (do not accidentally hurt the copper wire), count the number of copper wires, and then measure the diameter of the copper wire with a micrometer. With these basic data, you can directly search the calculation formula of cable cross-section on the network, so you can know whether the wire is square.

As a buyer, you should have the basic knowledge of buying goods to avoid being cheated. To sum up, no matter what products you buy, you must be qualified and standard products, and you can not covet cheap products.