Engineering Drawing: Importance, Basic Components & Tips

Drawing is a means of communication; sometimes, what cannot be explained in words can be explained via drawings. When it comes to engineering drawings, these are meant to offer manufacturers an image of the components that are needed.

These engineering drawings are versatile. If you want to learn about what is engineering drawing, its significance, and other aspects, the guide below is for you. So, let's read.

Qu'est-ce que le dessin technique ?

Engineering drawings are technical drawings that represent the structure, shape, and dimensions of the component in a layout that turns out to be a plan. The engineering drawing includes the requirements that the engineering part has, and it even gives the concept of the design.

These drawings are used for conveying relevant information about the component and help in manufacturing it. The engineering drawing is the initial point, which helps with the further creation of the part.

The Importance of Engineering Drawing in Product Development

Engineering drawing is a visual representation of the component and includes its structure, dimensions, and tolerances. A single component in the manufacturing industry is manufactured by following the drawing, and it is approved.

The use of assembly drawing allows the engineer to help achieve the relevant function in the component, ensuring that the component meets the drawing or not.

How to Prepare an Engineering Drawing

In order to prepare engineering drawings, they need tools like calipers, drawing boards, rulers, paper, and round gauges, which are required if making the drawing manually. However, this easy CAD software is used for creating computer-based drawings. The CNC machines are then directed to take the instructions from the software, and the component is manufactured based on the given specifications.

When drawings are created in a computerized form, they can be modified when needed and also help to save time and effort.

Basic Components of an Engineering Drawing

The basic engineering drawing has some important components, and these are as follows:

Title Block

At the bottom of the page is a title block that has the information about the component. It includes the name of the part, the people who are working on it, the number of drawings, and other necessary information.

It even has details like the projection angle and the polish criteria for the surface. These blocks help offer an improved understanding of the components of drawing.

Coordinates

Engineering drawings, which are large and complex, have coordinates that are located along the boundary of the drawing. These offer a reference point when the content of the drawing is discussed.

Types of Lines

There is no one kind of line that you will witness in an engineering drawing; there are different types of lines, and these are as follows:

Continuous line

A continuous line is a common one, and it represents the physical boundary of the object. It helps to draw real objects, and there could be different thickness variations in the lines. The thicker ones are used for the outer contour, and the thinner ones are used for the inner contour.

Hidden lines

Hidden lines are those lines that are not visible and have designs that obstruct them. The interior step length in a part that runs down is featured with the help of a hidden line.

Center lines

Center lines are used for showing such components that have either holes or symmetrical features in a drawing.

Dimension lines

The data collected is described using extension lines. These lines are separated by two arrowheads on the dimension line.

Broken View Lines

The broken view lines appear when the view is broken. A component that has a length of 3000 mm and a width of 10 mm will have similar geometric characteristics, whereas a breakout will offer the details without utilizing much space.

Cutting plane lines

The cutting plane lines offer a path for the cutout in the cutout view. The cutting line will bring the two types of holes into a single view.

Dimensions and Measurements

A dimension is a value in numerical form that represents the orientation, size, and position of the component. The process of creating the drawing on the given size of the component is dimensioning.

It is important to understand the shape and size of the component before manufacturing it. The size and location of the different features of the component are highlighted by dimension specification.

Types of Views

There are different types of views, which are considered when manufacturing the component and creating its engineering drawings. The different views featured in the drawing of these components are as follows:

Orthographic View

The orthographic view is the core view of the engineering drawing, and it represents a 3D figure in 2D form. It offers all the information that is essential for producing the part, and in this, the distortion of the length is avoided. The common way of conveying the drawings in multiview includes the top, front, and side views of the part.

Isometric View

Isometric engineering drawings are for 3D components. After a comparison with the front view, the lines that are vertical remain vertical, and the parallel lines appear at an angle of 30 degrees. The parallel lines and the vertical lines have an accurate length, and you can measure them using a ruler.

Partial View

The partial view consists of achieving a view by protecting a part of the component on the projection plane. Letters and arrows can indicate the expressed part and its projection direction. The configured and basic view can be achieved in the form of a local view.

Detail View

The detailed view is meant to show the model of the component completely. The detail view shows fine details of every feature a component may have.

Auxiliary View

Auxiliary view represents the inclined surfaces with no barriers, it represents a non-vertical and non-horizontal plane orthographic view.

Oblique View

The oblique view represents the view of an object that is featured on a plane that is unparalleled to the projection plane. It is the view towards and has a ladder or an arrow, which indicates the projection direction.

Sectional View

A sectional view is a type of view of the component that represents the inner part of the component when it is being cut. It has three different types, and these are as follows:

• The full sectional view consists of a full section when the cutting plane line passes through the object completely.
• The semi-sectional view is a type of view that shows a component having a symmetrical plane. The centerline of the symmetrical plane is half drawn in the form of a sectional view and the other half as a normal view.
• Broken-out sections feature the inner details of the component model by cutting the material at a depth that has been determined beforehand.

Cross-sectional Views

Cross-sectional views show the object’s cross-sectional area, which shows an orthographic projection of the cross-section of the component, which is the same as its entire area.

Partial Enlargement View

Partial views in the engineering drawings make it easier to have such parts that have a more detailed view.

Assembly Drawings

One of the big mistakes that engineers end up making is adding all the information about the part of the component completely in the assembly drawing. It is important to avoid this so that the assembly process is well facilitated.

You can use different tools like cuts, general dimensions, numbered pieces, and section views. Regardless of the attachment method, the component’s location of assembly would be apparent.

It is important to ensure that the materials information, quantity, part numbers, and names are present so that the assembly drawing for the project is created. It helps to make the process of manufacturing efficient.

Are There Standards and Conventions in Engineering Drawing?

There are various standards like ASME Y14.5, BS 8888, ISO 128, JIS B 0001, DIN, and GOST R 21.1101. These standards are meant to look into the dimension and tolerancing, followed by geometrical specifications.

Common Mistakes in Engineering Drawing

Some of the common mistakes made in the engineering drawings are as follows:

• The dimensions are either incomplete marks or messy. Some of them are even omitted or have repeated markings. Hence, the important dimensions should be marked appropriately, and the closed dimension appearance must be avoided.
• Incorrect placement of views is also a major issue, as it impacts the expression of design intent.
• The dimensional accuracy of the workpiece, when high and not marked, may lead to errors during machining.
• The technical part requirements, when not marked according to standardization, cause a major error.

Useful Tips for Creating Engineering Drawings

When creating the engineering drawings, some of the useful tips that are important to consider are as follows:

• Make sure to add only the dimensions of the crucial components and not all of them.
• The measurement of exact thread depth is challenging; hence, always threading the depth call-out at its minimum.
• If there are similar features in multiple views, give a dimension for a single feature only.
• If the process of production also has to undergo the assembly process, make sure to use this instruction in your engineering drawing.
• Assign tolerance to the critical features only; over-tolerance may end up making the production process extremely costly and time-consuming.
• Make sure that the tolerance level falls within the standard range in order for the component to be accurate.

Conclusion

The significance of engineering drawing is crucial when it comes to manufacturing components for different applications. We at DEK offer to manufacture these components with high accuracy by giving the engineering drawing ample consideration. So, let us handle your next project with our engineering drawing created by our skilled engineers.