Various cast iron codes are composed of the first capital letter of the Chinese pinyin letter representing the characteristics of the cast iron. When the code letters of the names of the two kinds of cast iron are the same, it can be distinguished by adding lower case letters after the upper case letters. For cast iron with the same name, if it needs to be subdivided, take the first capital letter of the Chinese Pinyin with its subdivision characteristics and arrange it at the back.
Name, code and designation of cast iron:
| Cast iron designation | Code and brand | Representation method instance |
| Grey cast iron | HT | HT100 |
| Vermicular graphite cast iron | RuT | RuT400 |
| Ductile iron | QT | QT 400—17 |
| Black core malleable iron | KHT | KHT300-06 |
| White core malleable iron | KBT | KBT350-04 |
| Pearlite malleable cast iron | KZT | KZT450-06 |
| Wear resistant cast iron | MT Cu1PTi | MT Cu1PTi-150 |
| Wear resistant white cast iron | KmBT | KmBTMn5Mo2Cu |
| Wear resistant nodular cast iron | KmQT | KmQTMn6 |
| Chilled cast iron | LT | LTCrMoR |
| Corrosion resistant cast iron | ST | STSi15R |
| Corrosion resistant nodular cast iron | SQT | SQTAl15Si5 |
| Heat resistant cast iron | RT | RTCr2 |
| Heat resistant nodular cast iron | RQT | RQTA16 |
A group of numbers after the code in the brand indicates the tensile strength value; When there are two groups of numbers, the first group represents the tensile strength value and the second group represents the elongation value. The two groups of numbers are separated by “one”.
Alloy elements are represented by international element symbols. When the content is greater than or equal to 1%, it is represented by an integer: when the content is less than 1%, it is generally not marked. Conventional elements (C, Si, Mn, s, P) are generally not marked, and their element symbols and contents are marked only when they have special functions.