Limits, Fits and Tolerances

        Basic Size            Tolerances                       Types of Fits                  Allowance             Systems
                                                              
         - Nominal                    - Unilateral                     - Clearance                     - Difference 
         - Based on                   - Bilateral                       - Interference                  between LLH 
         which limits                 - Compound                       - Transition                     and HLS
         are derived                                                 

                                      Geometric                                                ISO System
                                      Tolerances

                                      - Position
                                      - Form
                                      - Orientation
                                      - Runs, etc.
                                                                                                         Fundamental
                                                                                                         Tolerances
                                                                                                         
                                                                                                         - Grades IT01 to 
                                                                                                         IT16
                                                                                                         
                                                                                                         - Depends on
                                                                                                         basic size
                                                                                                         
          Hole and                                                                                       
          Shaft System                                                                                  
                                                                                                         British System
                                                                                                         
                                                                                                         - Specification
                                                                                                         using H,d etc
                                                                                                         
                                                                                                         - GO and NOT GO
                                                                                                         gauges