Basic conventions and applications for leader lines and reference lines

Basic conventions and applications for leader lines and reference lines
1 Scope
This part of ISO 128 specifies general rules on the presentation of leader and reference lines and their components as
well as on the arrangement of instructions on or at leader lines in all kinds of technical documents.
2 Normative reference
The following normative document contains provisions which, through reference in this text, constitute provisions of
this part of ISO 128. For dated references, subsequent amendments to, or revisions of, any of these publications do
not apply. However, parties to agreements based on this part of ISO 128 are encouraged to investigate the
possibility of applying the most recent edition of the normative document indicated below. For undated references,
the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of
currently valid International Standards.
ISO 128-20:1996, Technical drawings — General principles of presentation — Part 20: Basic conventions for lines.
3 Terms and definitions
For the purposes of this part of ISO 128, the following terms and definitions apply.
3.1
leader line
continuous narrow line which establishes the connection between the features of a graphical representation and
additional alphanumeric and/or written instructions (notes, technical requirements, item references, etc.) in an
unambiguous manner
3.2
reference line
continuous narrow line connecting with the leader line horizontally or vertically and on or at which the additional
instructions are indicated
4 Presentation of leader lines
Leader lines are executed as continuous narrow lines in accordance with ISO 128-20. They are drawn preferably at an
angle to the relevant representation and/or the frame limiting the drawing sheet, and not parallel to adjacent lines, e.g.
hatching lines. The inclination to the relevant lines shall be . 15°. See Figures 1 to 13.
Leader lines may be drawn with sharp kinks (see Figure 5), and two or more leader lines may be joined up (see
Figures 2, 5, 7, 8 and 11). They should not cross other leader lines, reference lines or indications, such as graphical
symbols or dimensional values.
1
This is a free 5 page sample. Access the full version online.