Drawing Standards - AS1100

This page will describe to you a number of the drawing standards that will be required when completing your drawings in Industrial Technology - Graphics.

Arrowheads:

Arrowheads shall be well defined. They may be open or solid and should comply with the forms and proportions. The length should be from 3 mm to 5 mm

Lines:

There are a number of different lines that you will be required to use in Technical Drawing. The table below shows you the different lines, describes where they are used and give you an example of each line.

Where two or more lines of different type coincide, the following order of priority should be observed:

Views:

Selection of views shall be selected according to the following principles:

(a) To reduce the number of views required to fully delineate the information to be specified.

(b) To avoid the need for hidden outlines.

(c) To avoid unnecessary repetition of detail.

Sectioned views:

Sectioning is used to show internal detail or to reduce the use of hidden detail lines that may make the object difficult to recognise.  All hidden outlines in the section should be omitted except in special cases. 

These types of drawings are Orthogonal's with imaginary lines cutting the object into parts.

Each sectional view or section shall be identified with its appropriate cutting plane, where identified, by inscribing a subtitle below the view or section; e.g. ‘SECTION A-A’, ‘SECTION B-B’.

Cutting planes are to shown using a "Type H" line with the direction of viewing show by an arrowhead and a letter placed at the tail of the arrow. The cutting plane should pass through the main part of the object.

Hatching:

The cut part of the object is to be shown using with a hatched line (usually at 45°, unless this would make the object more difficult to understand). Where two or more adjacent parts have been sectioned the hatch line should be at different angles.

If the object has a web support and the section plane passes along this then the web is not sectioned, although if the section plan passes through it then the web is sectioned (See image below).

Note: In section A-A passes along the web and therefore is not hatched in the side view, although in section B-B the plane passes thought the web and is shown in the bottom view.

Breaks:

Break maybe used to shorten lone objects and will use Type C or Type D lines.

Symbols:

The following symbols are to be used in dimensioning:

Dimensioning, Projection and Leader Lines:

Objects that are drawn in Graphics often need to have dimensions showing the size and angles used to show detail about the component. Dimensions show the length and angle of items and the drawing should include only the measurements require to describe the object. 

Projection lines are lines that extend from the object and extend outside the outline of the drawing where possible. These lines should start and extend past the dimension line.