Iso 2768 Mk
Variations on dimensions without tolerance values are according to ' ISO 2768'. All tolerance limits are given in mm. ISO 2768 and derivative geometrical tolerance standards are intendedto simplify drawing specifications for mechanical tolerances. ISO 2768 is mainly for parts that are manufactured by way of machining or removal of materials. General tolerance ISO 2768 does not specify where to use these tolerances. As per design requirements and manufacturing capability tolerance class is defined. For example: For sheet metal parts ISO 27 68 – mk is used. And for machined components ISO 27 68 – fh can be used.
ISO 2768-mK and gage size
ISO 2768-mK and gage size
If an outside cylindrical surface (defined on a drawing calling out ISO 2768-mK and DIN 7167) has a diameter of Ø12mm (+0.2 / -0.1) what would the correct “GO” gage size dimension (inside diameter of the gage) to verify this OD requirement?
I would appreciate someone with ISO knowledge to help me getting the right gage size.
I looked up online for DIN 7167 and found some recommendation such as: ”The issuing body recommends using DIN EN ISO 14405-1:2011-04 .”
I did not see DIN 7167 having the envelope requirement by default so, I am little bit confused about the appropriate gage dimension.
Any help will be greatly appreciated.
Thank you
ISO 2768 Part 1 is intended to simplify drawing indications and it specifies general tolerances for linear and angular dimensions without individual tolerance indications in four tolerance classes. It applies to the dimensions of parts that are produced by metal removal or parts that are formed with sheet metal fabrication.
ISO 2768 Part 1 only applies to the following dimensions which do not have an individual tolerance indication:
Iso 2768 Mk-e
a) linear dimensions (e.g. external sizes, internal sizes, step sizes, diameters, radii, distances, external radii and chamfer heights for broken edges);
b) angular dimensions, including angular dimensions usually not indicated, e.g. right angles (90°). unless reference to ISO 2768-2 is made, or angles of uniform polygons;
c) linear and angular dimensions produced by machining assembled parts.
It does not apply for the following dimensions:
Iso 2768 Mh Tolerances On Drawings
a) linear and angular dimensions which are covered by reference to other standards on general tolerances;
b) auxiliary dimensions indicated in brackets;
c) theoretically exact dimensions indicated in rectangular frames.
Note:
1. These tolerances may be suitable for use with materials other than metal.
2. When selecting the tolerance class, the respective customary workshop accuracy has to be taken into consideration.
3. Smaller or larger tolerances should be indicated adjacent to the relevant nominal dimensions.
4. General tolerances specified in angular units control only the general orientation of lines or line elements of surfaces, but not their form deviations.
Iso 2768 Mk Internal Radius
5. If general tolerances in accordance with ISO 2768 shall apply, the information shall be indicated in or near the title block, such as ISO 2768-m.