According to the size of the member to be connected to determine the size of the code and the type and material types. Angular codes are often used in decorative engineering and furniture assembly. Such as curtain wall installation is the angle code to connect.
The corner code is the number at the playing card corner, such as A, K, 8 and so on, but there is no corner code in early poker (see picture). The biggest problem with this type of poker is that it is necessary to see the whole poker in order to know The size of the poker point. It was not until 1870 that American corners were invented.