The rated load of forklift loader , also known as the provisions of labeled load, is unknown to many users. Therefore, when purchasing fork installation machine, they will blindly trust the sales staff, which will be cheated to a certain extent. According to "Technical Conditions of National Standard Fork Installation" and "Test Methods of National Standard Fork Installation", when the manufacturer marks the rated load of the fork installation machine, it is also the contract load agreed between the manufacturer and the buyer, that is, the rated load should be less than or equal to the tipping load of the whole machine. Since the user has no professional calculation method, there is a simple empirical algorithm: the rated load should be less than or equal to 90% of the operating weight of the whole machine.