Preface
This new edition of CSA Standard CAN3-B78.1-M, Technical Drawings-General Principles, supersedes the second edition published in 1967 as Mechanical Engineering Drawing Standards, Drafting Practices-General Principles.
The second published Canadian drawing standard resulted from discussions a t ABCA conferences and joint meetings with the Canadian Government Specifications Board Committee on Drawing Practices. While not by any means a complete unified ABCA Standard, B78.1-1967 was in general agreement with BS308, MIL Standards, and drafts of USA Standard Y14.
It is gratifying to note that there has been a wide distribution of the 1967 issue. It has been used as a text in a large number of Canadian educational establishments and has been adopted for use by all Canadian Government agencies and, in whole or in part, by a fairly large and increasing number of industrial firms of all sizes.
As a result, a number of very valuable and constructive comments have been received from users all over Canada and from the ABCA partners. These are gratefully acknowledged.
Acknowledgement is also made for the use of many illustrations, figures, and appendices taken from BS308, USA Standard Y14, SAE, and US MIL Standards.
This new edition also incorporates the agreements reached at the ABCA meetings held in Ottawa in 1977.
This Standard specifies the general principles of presentation to be applied to all kinds of technical drawings (mechanical, electrical, civil engineering, architectural, etc). It is possible that in some specific technical areas the general rules and conventions do not adequately cover all the needs of specialized practices. In these cases additional rules are required, which may be specified in particular standards for these areas. The general principles should be respected, however, in order to facilitate exchange of drawings and to ensure the coherence of drawings in a comprehensive system relating to several technical functions.
The figures used in the text of this Standard are complete only in so far as is necessary to illustrate the point in question; they are not intended to be fully dimensioned working drawings. Descriptive notes to support the text, which normally would not be part of a drawing, are in lower case lettering.
This Standard was prepared by the Committee on Technical Drawings under the jurisdiction of the Steering Committee on Mechanical and General Engineering Work, and was formally approved by these Committees. It has been approved as a National Standard of Canada by the Standards Council of Canada.
Scope
1.1
This Standard is intended to cover the field of technical drawing practice. It applies primarily to end-product drawings, which usually consist of detail drawings, and assembly or subassembly drawings, but is not intended to fully cover other supplementary drawings such as check lists, schematic diagrams, electrical wiring diagrams, flow charts, installation drawings, and process drawings, nor pictorial drawings or building drawings.
1.2
For preparation of building drawings, see CSA Standard CAN3-B78.3-M, Building Drawings; for preparation of electrical/electronics diagrams, see CSA Standard B78.4, Electrical and Electronics Diagrams; and for deviations from B78.1 in structural drawings see Appendix A.
1.3
This Standard is based on the premise that drawings made in accordance with its requirements will be suitable for reproduction by various modern processes, including microfilming, and shall meet the requirements of CGSB Standard CAN2-72.7-M, Drafting Requirements for Drawings to be Microfilmed.
1.4
All linear dimensions in this Standard are shown in millimetres (mm) unless otherwise indicated.
1.5
The contents of this Standard is equivalent to the contents of the international standards listed in Appendix C.
