CSA B78.2 : 0

Technical Committee on Technical Drawings
Preface
1 Scope
2 Reference Publications
3 Definitions of Terms
4 Fundamental Rules
    4.1 General
    4.2 Four Aspects of Each Feature
    4.3 Implied Geometric Form
    4.4 Relationship Between Requirements
    4.5 Specification of Values for Dimensions and
          Tolerances
    4.6 Indicating Manufacturing Operations
    4.7 Free State and Orientation
    4.8 Rules for Geometrical Tolerancing
5 Symbology
    5.1 General
    5.2 Use of Notes to Supplement Symbols
    5.3 Symbol Construction
6 Elements of Dimensioning
    6.1 Scope
    6.2 Application
    6.3 Dimensioning Units
    6.4 Line Conventions
    6.5 Extension (Projection) Lines
    6.6 Dimension Lines
    6.7 Centre Lines
    6.8 Dimension Line Termination
    6.9 Leaders
    6.10 Placement of Values
    6.11 Basic (Exact) Dimensions
    6.12 Not to Scale
    6.13 Choice of Dimensions
7 Dimensioning Common Features
    7.1 Diameters
    7.2 Radii
    7.3 Rounded Ends and Slotted Holes
    7.4 Counterbored and Spot-Faced Holes
    7.5 Countersunk and Counterdrilled Holes
    7.6 Chords, Arcs and Angles
    7.7 Profiles
    7.8 Symmetrical Outlines
    7.9 Square Features
    7.10 Machining Centres
    7.11 Chamfers
    7.12 Slopes
    7.13 Tapers
    7.14 Keyseats
    7.15 Knurls
    7.16 Undercuts
    7.17 Rod and Tube Detail
    7.18 ISO Metric Screw Threads
    7.19 Pipe Threads
    7.20 Surface Texture
    7.21 Gears and Splines
    7.22 Castings
    7.23 Forgings
8 Location of Features
    8.1 General
    8.2 Rectangular Co-ordinates
    8.3 Polar Co-ordinates
    8.4 Point-to-Point Dimensioning
    8.5 Common-Point Dimensioning
    8.6 Arrowless Dimensioning
    8.7 Tabular Dimensioning
    8.8 Repetitive Features and Dimensions
    8.9 Other Dimensioning Methods
9 Datums
    9.1 General
    9.2 Three-Plane Datum System
    9.3 Selection of Manufacturing Datum Features
    9.4 Identification of Datum Features
    9.5 Datum Targets
    9.6 Datum Features
    9.7 Datums on a Maximum Material Condition (MMC) Basis
    9.8 Combining the Datum Feature Indicator with a
          Dimension Line
10 General Tolerancing and Related Principles
    10.1 General
    10.2 Direct Tolerancing Methods
    10.3 Tolerance Expressions
    10.4 Indication of Fits and Tolerances on Drawings
          Assembled Parts
    10.5 General Tolerance Notes
    10.6 Interpretation of Tolerances
    10.7 Effect of Surface Coatings
    10.8 Tolerance Accumulation
    10.9 Limits of Size
    10.10 Screw Threads
    10.11 Gears and Splines
    10.12 Sloped Surfaces
    10.13 Tapers
    10.14 Tangent Radii
11 Geometrical Tolerancing
    11.1 General
    11.2 Geometrical Characteristics
    11.3 Relationship to Feature Size - Regardless of
          Feature Size (RFS)
    11.4 Relationship to Feature Size - Maximum Material
          Condition (MMC)
    11.5 Tolerance Notes and Symbols
    11.6 Application of Symbols to Drawings
    11.7 Application of Symbols with Datum Systems
    11.8 Interdependence of Geometrical Tolerances
12 Tolerances of Location
    12.1 General
    12.2 Direct Tolerancing
    12.3 Positional Tolerancing
    12.4 Location of Groups of Features
    12.5 Feature Pattern Location - Composite Positional
          Tolerancing
    12.6 Projected Tolerance Zone
    12.7 Counterbored Holes
    12.8 Closer Control at One End of a Feature
    12.9 Control in Two Directions
    12.10 Noncylindrical Features
    12.11 Coaxiality Controls
    12.12 Symmetry
    12.13 Spherical Features
13 Tolerances of Form, Orientation, Profile and Runout
    13.1 General
    13.2 Form and Orientation Tolerances
    13.3 Profile Tolerances
    13.4 Runout Tolerance
    13.5 Free State Variation
14 Dimensioning of Casting Drawings
    14.1 General
    14.2 Casting Datums
    14.3 Machining Datums
    14.4 Dimensions
    14.5 Draft
    14.6 Cored Holes for Threads
    14.7 Fillets and Radii
    14.8 Machining Allowances
15 Dimensioning for Computer-Aided Design and Computer-
    Aided Manufacturing Mode
    15.1 General
    15.2 Co-ordinate System
    15.3 Reference Planes
    15.4 Reference Axes
    15.5 Mathematical Quadrants
    15.6 Dimensioning and Tolerancing
    15.7 Incorporating Dimensional Changes
16 Formulas for Positional Tolerancing
    16.1 General
    16.2 Formula Symbols
    16.3 Floating Fastener Case
    16.4 Fixed Fastener Case
    16.5 Coaxial Features
    16.6 Perpendicularity Errors
17 Form, Proportion and Comparison of Symbols
    17.1 General
    17.2 Form and Proportion
    17.3 Comparison
Appendices
A Information on Obtaining Publications Referred to
    in this Standard
B Bibliography of International Standards
C Variances in Drawing Practice Standards

It is complementary to CSA Standard CAN3-B78.1, and covers dimensioning and tolerancing of products depicted on technical drawings.