International standard tire code, which expresses the percentage of section width and flattening rate in millimeters. Add: tire type code, rim diameter (inch), load index (allowable bearing mass code) and allowable speed code.
For example, the meaning represented by 185/75R 15 77H:
185 means that the tire width is185 mm.
75 indicates that the flat rate of the tire section is 75%, that is, the height of the section is 75% of the width.
R stands for radial tire.
15 represents the rim diameter of 15 inch.
77 stands for load index.
H stands for the allowable speed of class H.
Extended data
According to China's regulations, in addition to the tire size, the manufacturer's trademark, grade, maximum load, corresponding air pressure and production number should also be marked on both sides of the tire. In order to easily identify the carcass cord, the sidewall is also marked with Chinese phonetic alphabet.
For example, m (or no words) stands for cotton tire, r stands for rayon cord tire, n stands for nylon tire, z stands for radial tire, g stands for steel wire tire, ZG stands for steel wire meridian and so on.
Nowadays, automobile tires are further flattened, and the flattening rate [(H/B)x 100] tends to be above 50-70, 50, 55, 60, 65 and 70 from 60-80, and a few automobiles have already used specifications 40 and 45.
The latest tire series representation method in the United States is based on the "flat rate" using the "letter-number" symbol. For example, a tire is labeled F78- 14, where f represents the bearing capacity of the tire.
The first number indicates that the "flattening rate" is H/Bx 100, and the number 78 indicates that the tire height is 78% of the width. The lower the value, the flatter the tire section. The second number 14 indicates that the rim diameter is 14 inch.
The unit of bearing capacity is kg, and the letters indicating the bearing capacity and the load it bears are as follows: A-4 10, B-445, C-480, D-5 10, E-540, F-580, G-620, H-685, I-.
References:
Baidu encyclopedia-tires (round elastic rubber products assembled on vehicles or machinery)