CNC Machining accuracy classification

The machining accuracy is measured by tolerance grade. The smaller the grade value is, the higher the precision will be. Machining error is represented by numerical value. The larger the value, the greater the error. High machining accuracy means small machining error and vice versa. There are 20 tolerance grades from IT01, IT0, IT1, IT2, IT3 to IT18, among which IT01 indicates that the machining accuracy of this part is the highest.

Generally speaking, IT6 is widely used in machining important matching index according to the classification of international accuracy tolerance grade. IT6 indicates that the mating surface requires high uniformity, which can ensure a relatively high mating property. It is stable and reliable to use, and the machining center can complete drilling, milling, boring, expanding, hinge, rigid tapping and other processes.