A | B |
Dimension lines | Terminated by arrowheads |
Dimension lines | Shows the beginning and the end of the measurement |
Dimension lines | Thin line weight |
Dimension lines | Should be broken to allow for the numbers to be inserted |
Dimension lines | minimum of 3/8" away from the object |
Dimension lines | minimum of 1/4" away from parallel dimension lines |
Extension lines | 1. Extend the edge of the object |
Extension lines | Thin line |
Extension lines | 1/16" gap between the object and the start of the extension line |
Extension lines | Extend about 1/8" beyond the last dimension line |
Leaders | Are drawn at an angle (usually 30°, 45°, or 60°). |
Leaders | have a short (1/8") shoulder |
Leaders | end with an arrowhead |
Leaders | should not cross over dimension lines |
Leaders | Avoid making parallel or perpendicular to visible edges |
Leaders | extend from the first word or the last word of the note |
Arrowheads | Can be solid filled or open |
Arrowheads | 1/8" long |
Arrowheads | 3 times as long as wide |
Fractional inches | Used where close tolerances are not important |
Fractional inches | The fraction bar is horizontal |
Fractional inches | Omit the inch mark |
Metric | millimeter is the standard unit of measure |
Metric | abbreviation for millimeters (mm) is usually omitted |
Metric | If the value is less than one millimeter, a zero should precede the decimal point |
Decimal inches | Omit zero before the decimal point for values of less than one |
Decimal inches | should be rounded to two decimal places |
Decimal inches | the ANSI standard |
clarity | number one rule of dimensioning |
dimensions | placed where the shape is best shown |
dimensions | Shortest placed closest to the object |
dimensions | Group and align when possible |
dimensions | 5. Avoid duplicate and/or unnecessary |
dimensions | Do not place to coincide with a line of a drawing |
dimensions | Avoid crowding |
dimensions | avoid placing inside a view |
dimensions | Avoid hidden features |
dimensions | Place between views to which they relate |
dimension lines | thin and dark |
dimension lines | contrast noticeably with visible lines |
dimensions | describe both size and location of features |
Arcs | Dimension by using the radius |
Circles | Dimension by using the diameter |
Circles | symbol precedes the circle size |
circles | Use a "X" when describing quantity |