Types of Lines AND Their Applications
Engineering Drawings or Technical Drawings are comprised of various types of lines. Similarly as for any language with letter sets and grammar.
Remember! Engineering Drawing is also a Universal Language in the field of Engineering. Lines of various thicknesses and highlights are utilized for explicit uses.
Specialized drawings are drawn with various kinds of lines. By appropriate decision and utilization of lines, items can be accurately characterized in a drawing. Various kinds of lines prescribed for explicit applications are surrendered.
There are a total of Ten kinds of lines that are generally utilized as a rule of Engineering Drawing or Design drawing according to IS:10714-1983.
Although in some of the cases, there are two alternatives of lines available as described in the above Table-1 of Types of Line AND Their Application yet it is recommended that only one type of line ought to be used on any one drawing.
As described previously, there are ten types of lines in the Types of Line AND Their Application chart.
Continuous Thick Lines :
As already stated in Table - 1, Continuous Thick Lines ( A Type Lines ) are used to draw Visible Outlines ( A1 ) and Visible Edges ( A2 ) of any object ( See the image below ).
For this reason, Continuous Thick Lines are also termed as Object Lines. As per the BIS system, the thickness of Continuous Thick Lines should be 0•5 mm.
According to the BIS system, a Types of Line AND Their Application chart-1 or table-1 is shown above.
All types of lines mentioned in the above chart are very much suited for any branch of engineering drawing, especially for production & construction drawings.
Continuous Thin Lines
Continuous thin lines are also used to draw leader lines, hatching lines, outlines of revolved sections, short center lines, diagonal lines, thread lines, limit of partial or interrupted sections ( if the line is not a chain thin line ), and broken sections.
Chain Thin Lines
Chain thin lines are basically used to draw center lines of circles or axis lines of circular objects. It is also used to draw lines of symmetry, and trajectory as said in the above chart.
Cutting Plane Line
A cutting plane line is also termed a section line as this type of line is used for indicating the direction of the cut or section on a workpiece. It is like a chain thin line with two thick ends as shown in the chart or below image.
Chain Thick Lines
Chain thick lines are used to direct or indicate on surfaces to which a special operation ex. turning, sharpening, surface finishing, etc. need to be performed.Dashed Lines
What is a Centroidal Line?
Simply, the centroid is the center or middle point of any object rather than a circle or circular object. For circle or circular objects, the middle point is termed as the Center but for objects rather than the circle or circular object (Ex. triangle or triangular, square, quadrilateral, etc), the middle point is termed as the Centroid.
In engineering drawing, the line that we use to indicate the center of any object except for a circular object, is termed a Centroidal Line. Its application is similar to the center line of any circular object.
A Centroidal Line is determined by a chain thin line with a long dash and double short dash alternatively on an image of a symmetric object. You can see this in the "J" row on the above chart.