International Tolerance Grades – ITOl to IT16 – Limits and Fits - Explained
IT01, IT0, IT1, IT2, IT3, IT4, IT5, IT6, IT7, IT8, IT9, IT10, IT11, IT12, IT13, IT14, IT15, IT16 are the 18 standard tolerance grades (IT01, IT0, IT1 through IT16) avaliable on International tolerance grades. These variation in part size, also called the magnitude of the tolerance zone, is expressed in grade or IT numbers. Seven grade numbers are used for high-precision parts; these are IT01, IT0, IT1, IT2, IT3, IT4, IT5.
The most commonly used grade numbers are IT6 through IT16, and these are based
on the Renard R5 geometric series of numbers. For these, the basic equation is
where D is the geometric mean of the size range under consideration and is obtained from the formula
The ranges of basic sizes up to 1000 mm for use in this equation are shown in Table
With D determined, tolerance grades IT01 through IT16 are found using Eq.and the following table
Labels: Engineering Standards and Codes, feature, Limits And Fits
Labels: Engineering Standards and Codes, feature, Limits And Fits


