When there is no need to change tires:
The damaged diameter of the tread is less than 6mm: In daily use, the most common vehicle is nailed, but most of them can't be found at that time. Inserting the nail into the tire will not damage the structure of the tire to a great extent. There is just a hole in the steel wire, curtain cloth and polyester layer. Just fix it.
Excessive tread damage: the tread touches sharp objects, the pattern falls off seriously, and the carcass cracks. After the hole diameter of the punctured tread exceeds 6mm, it cannot be used again. A flat tire must be replaced to ensure driving safety.
Bulging: Bulging is caused by the breakage of the cord of the ply. In this case, the tire must be replaced immediately. If it is not replaced in time, there may be a danger of puncture.
Extended data:
Tire is a round elastic rubber product that is assembled on various vehicles or machinery and rolls on the ground. Usually installed on the metal rim, it can support the car body, buffer the external impact, achieve contact with the road surface and ensure the driving performance of the vehicle.
Tires are often used in complex and harsh conditions. They are subjected to various deformations, loads, forces and high and low temperatures during driving, so they must have high bearing performance, traction performance and cushioning performance. At the same time, it also requires high wear resistance and bending flexibility, as well as low rolling resistance and heat generation. Half of the world's rubber consumption is used for tire production, which shows the ability of tire to consume rubber.
References:
Tire-Baidu Encyclopedia