BS EN ISO 128-3:2020 pdf free.Technical product documentation – General principles of representation.Views, sections and cuts.
BS EN ISO 128-3 When the scale of a technical drawing does not allow all features to be clearly shown or dimensioned,the unclear features shall be enclosed or encircled by a continuous narrow line (type 01.1), with the area thus enclosed identified by a capital letter. The features in the area shall also be shown on an enlarged scale, in a view that is broken with a continuous narrow freehand/free formed curve line (type 01.1). This shall be accompanied by the identification letter and an indication of the scale beside it between parentheses, as shown in Figure 8. The rules for lettering height are discussed in Annex A.The position of the cutting plane(s) shall be indicated by means of a cutting line represented with a dashed dotted wide line (type 10.2) according to ISO 128-2:一, Annex E and Annex G. A straight cutting plane shall be drawn (see Figure 12). If the cutting plane changes its direction, the cutting line should only be drawn at the ends of the cutting plane, where the cutting plane changes direction (see Figure 13). If necessary for its legibility, the cutting line may be connected with a long-dashed dotted narrow line of the type 04.1 according to ISO 128-2:一, Annex D or 04.1 according to ISO 128-2:一, Annex F). The direction of viewing for the relevant cut and section is indicated by the reference arrows as defined in Annex A. The designated cut and section can be located irrespective of the view in which the cutting plane is taken. Representation of areas on cuts and sections is covered in Clause 7.Each cut and section plane shall be given clear identification with twice the same capital letter, once at each of the cut and section arrows. This identification should be positioned for reading from the bottom of the technical drawing. The 30° or 90° cut and section arrow is defined in A.4, as is the lettering height of the identification. BS EN ISO 128-3 pdf download.