Look at the quality system certification
See if there is a quality system certificate; See if the certificate is standardized; See if there is a factory name, address, inspection stamp and production date; See if there are any trademarks, specifications, voltages, etc. Printed on the wire.
Try to feel
It is recommended to bend the end of the wire repeatedly by hand. All products with soft hand feel, good fatigue strength, elasticity in plastic or rubber, and no crack on conductor insulator are excellent products.
say/call
High quality welding wire is usually within the specified weight range. For example, the common plastic insulated single-stranded copper conductor with a cross-sectional area of 1.5mm2, per 100 m weight1.8 ~1.9kg; 2.5mm2 plastic insulated single-stranded copper core wire, with a weight of 3 ~ 3 100 m1kg; The weight of 4.0mm2 plastic insulated single copper core wire is 4.4 ~ 4.6kg1300m.
Look at the copper.
Qualified copper core wire copper core should be purple, shiny and soft to the touch. False copper core wire is purple-black, yellow or white, with many impurities and poor mechanical strength and toughness. It will break with a little force, often breaking wires.
Look at the price
Because of the low production cost of fake and shoddy wires, vendors often sell them at low prices under the guise of good quality and low price, which makes people fall for it.