It applies to the dimensions of work pieces that are produced by metal removal or are formed from sheet metal. This part is intended to simplify drawing indications and specifies general tolerances in four tolerance classes.
Part 1: Tolerances for linear and angular dimensions without individual tolerance indications
ISO 2768 consists of the following parts, under the general title General tolerances: This first edition of ISO 2768-1, together with ISO 2768-2 : 1989, cancel and replace ISO 2768 : 1973. International Standard ISO 2768-1 was prepared by Technical Committee ISO/TC 3, Limits and fits. They are approved in accordance with ISO procedures requiring at least 75% approval by the member bodies voting. Symmetry (Position for ISO G&T Standard not-ASME or ANSI GD&T) Ranges in nominal lengths in mmĭraft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. Perpendicularity Ranges in nominal lengths in mm Straightness and Flatness Ranges in nominal lengths in mm
Tolerance class designation (description)Įxternal Radius and Chamfer Heights Permissible deviations in mm for ranges in nominal lengthsĪngular Dimensions Permissible deviations in degrees and minutes for ranges in nominal lengths Linear Dimensions Permissible deviations in mm for ranges in nominal lengths ISO 2768 is mainly for parts that are manufactured by way of machining or removal of materials. ISO 2768 and derivative geometrical tolerance standards are intended to simplify drawing specifications for mechanical tolerances. Variations on dimensions without tolerance values are according to ” ISO 2768″. Technical drawings - Fundamental tolerancing principle. Geometrical tolerances for features without individual tolerance indications. ISO 2768-2 : 1989, General tolerances - Part 2: And for machined components ISO 2768–fh can be used. For example : for sheet metal parts ISO 2768–mk is used. Tolerance class is defined as per design requirements and manufacturing capability. General tolerance ISO 2768 does not specify where to use these tolerances. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. Variations on dimensions without tolerance values are according to ISO 2768, all tolerance limits are given in mm. If I find some time tomorrow, I will see if I can scan my tables and send them to you.ISO 2768 and derivative geometrical tolerance standards ISO 2768–mk and ISO 2768–fh are intended to simplify drawing specifications for mechanical tolerances. I wish I had a copy of the complete tables I could email you, the following link is mounting and dismounting catalog that has tables in the back, but does not have all of what you are looking for.
Are you sure you are not looking at H tolerance tables? The capital H is for holes and all of those are 0 to a plus number.Īfter you have used it a bit, these tolerances get easier. The +43 on the h9 tolerance is definitely wrong, all the h tolerances are +0 and a negative number. I'm using a book published by FAG Bearings that lists the complete tolerance range for each designation, I don't have my Machinerys Handbook here to check and see what is in there. Bearing tolerances are usually fairly tight since that controls the amount of internal clearance of the rolling elements to the race of the bearing when installed.Īn M6 tolerance on a 47mm bore should be -4 to -20 according to my book.