What is Engineering Drawing & Different Types of Lines in Engineering Drawing | CNCLATHING


In engineering drawing, the details of various objects are drawn by different types of lines. What types of lines used in engineering drawings and how they used? Keep reading for understanding the basic components of engineering drawing.

What is Engineering Drawing?

An engineering drawing is a type of technical drawing contains all the information of a product to be machined or fabricated, the purpose is to specify the geometry necessary for the construction of the product. Standardized languages and symbols are used to describe the dimensions, parameters, and other features of the objects, which helps people to understand the drawing and manufacture the part correctly. 


In most cases, a simple component is specified with many drawings, which are linked together with a primary drawing or assembly drawing. In addition, besides pictographic representations, additional textual explanations can be used to convey the necessary information. The following are the critical information of an engineering drawing of mechanical parts or CNC products.

Geometry – the shape of the object, represented as views from various angles

Dimensions – the size of the part, expressed in accepted units

Tolerances – variations of each dimension allowed

Material – represents what the component is made from

Finish – specifies the surface quality

Different Types of Lines in Engineering Drawing

A single drawing is composed of many basic elements, and different types of lines play distinct roles. A variety of line styles graphically represent physical objects, including visible, hidden, center, cutting plane, section, and phantom. Each style can be divided into different types. Let’s see what types of lines used in engineering drawings. 

A: Continuous Thick Line

This line is used to display the outline and edges of the main drawing, done with a pencil softer than HB.

B: Continuous Thin Line

This line is basically used for dimension, extension, projection, leader line, etc. A harder pencil should be used, such as a 2H pencil.

C: Continuous Thin Free Hand Line

This line is used to show short break or irregular boundaries.

D: Continuous Thin Zigzag Line

This line is used to show long break.

E: Dashed Line

This line is used to show hidden edges of the main object.

F: Chain Thin Line Long-Dotted (Dashed Thin Lines with Dots)

This line is used to represent the center line for circles and arcs.

G: Chain Thin with Thick Ends

This line is used to represent the location of a cutting plane. 

H: Long Thin Dashed and Double Short Dashed Lines

This line is located in front of cutting planes, outlines of adjacent parts, censorial Lines, and to state center of gravity.