Instruments Used in Engineering Drawing -its Uses and Importance

What is Engineering Drawing?

In engineering drawing, engineering related objects like buildings, walls, electrical fittings, pipes, machines etc. are represented with specifications like size, shape, materials etc.
Several engineering drawing software with more accuracy are available. But, drawing on paper is still being used in some areas and for small constructions.
Instruments Used in Engineering Drawing

Importance of Engineering Drawing

Drawing plays vital role in the engineering and construction works. The drawing requires no language any one can read it. So, drawings of other countries structures can also be studied easily.
The drawing improves the imagination and new inventions can be developed. The estimate for the project can be done using the details provided in the drawing.
The structure can be analyzed completely before construction by using drawing. So, every engineering construction department especially civil engineering requires drawing to start a project.

Importance of Engineering Drawing

Instruments Used in Engineering Drawing

The instruments used in engineering drawing are:
  1. Drawing sheet
  2. Drawing board
  3. Mini drafter
  4. T square
  5. Compass
  6. Divider
  7. Set squares
  8. Clinograph
  9. Protractor
  10. French curves
  11. Templates
  12. Pencils
  13. Eraser

Drawing Sheet

Drawing sheet is a white paper on which an object is drawn which is available in various sizes. The sheet used for engineering should be of good quality. It should be white in color with uniform thickness with must resist the easy torn of paper. The surface of sheet must be smooth.
Various sizes of drawing sheets recommended by Indian standards are listed below.
Drawing Sheet TypeDimensions (Length X Width) (mm)
A0841 X 1189
A1594 X 841
A2420 X 594
A3297 X 420
A4210 X 297
A5148 X 210
Drawing Sheet

Drawing Board

Drawing board is generally made of soft wood and it is in rectangular shape. It is used to support drawing sheet, so, the size of board is made according the size of the drawing sheet.
The wood portions are joined by tongue and grove type joint to prevent cracks. At the edge of board, straight ebony edge is provided for the T-square usage.
Different types of drawing boards and their sizes according to IS classification are listed below.
Type of Drawing BoardLength X Width X Thickness (mm)
D01500 X 1000 X 25
D11000 X 700 X 25
D2700 X 500 X 15
D3500 X 350 X 15
Drawing Board

Mini Drafter

Mini drafter is an instrument which can be used for multiple functions in drawing. It contains two arms which is adjustable to required angle and at the end of the lower arm a scale set is attached.
The scale set contains two scales connected perpendicular to each which cannot be separated. This instrument is fixed to the drawing board at one edge with the help of screw provided for the drafter.
Mini drafter is used for drawing horizontal lines, vertical lines, inclined lines, angles, parallel lines, perpendicular lines etc.
Mini Drafter

T-Square

T square is used to draw horizontal and vertical lines on drawing sheet. It made of wood or plastic and in T shape. The vertical part of T is called as blade and horizontal part of T is called as head.
The edge of head is uniform level and attached to the edge of the board. The working edge is used to draw lines anywhere on the sheet by moving the instrument top to bottom.
T-Square

Compass

Compass is used to draw an arc or circle with known dimensions on engineering drawing. It is generally made of steel and consists two legs. One leg contains needle at the bottom and other leg contains a ring in which a pencil is placed.
The needle tip is placed at the respected point and pencil tip is adjusted to the height at least 1mm just above the tip of the needle. The gap is nothing but the paper thickness.
Compass

Divider

The divider looks like a compass, but the difference is the two legs of divider are provided with needles. This is used to divide a line or curve into equal parts. It is also used to check the measurements.
Divider

Set Squares

Set squares are used to draw lines with an angle between them. In most of the structures, 30, 45, 60 and 90-degree lines are most common. So, set squares make the work easier for this type of drawings.
Generally, set squares are of two types. One is 45 degree set square and another one is called as 30 – 60 degree set square. Both are required in the drawing. 45 set square has a side of 25 cm while 30-60 set square has 25 cm length on one side.
Set Squares

Clinograph

Clinograph is an instrument used to draw parallel lines to the inclined lines. It contains one adjustable wing or strip which can be adjusted to required angle. So, it can be termed as adjustable set square.
Clinograph

Protractor

Protractor is used to draw and measure the angles of lines in the drawing. It is transparent and made of plastic. It is in the shape of semi-circle, and the edge of semi-circle part consists reading with one-degree accuracy.
The bottom line joins the 0o to the 180o. The center of this bottom line is marked as “O” or “C” from which the angles are measured.
Protractor

French Curves

French curves are made of plastic and they are in irregular shapes. Sometimes the drawing requires irregular curves or shapes or arcs which cannot be drawn using compass. In that case French curves are suitable.
Generally French curves are more suitable for small curves and for long curves splines are used.
French Curves

Drawing Templates

Templates are nothing but plastic or wooden boards which contains spaces of several shapes or letters. Non-dimensional shapes or variety font letters are drawn by using templates which makes drawing easier and perfect.
Drawing Templates

Pencils

Pencil is used to draw on the paper. Any type of pencil is not suitable for drawing. There are some limitations, the drawing appearance should be very neat and understandable.
Every line of the drawing should indicate its importance. It depends upon the hardness of pencil.
Based on the hardness quality pencils are classified into 18 grades and they are
Grade of PencilHardness of Pencil
9HHardest
6H, 5H, 4HExtremely Hard
3HVery hard
2HHard
HModerately hard
FFirm
HBMedium hard
BModerately soft and black
2BSoft and black
3BVery soft and black
4B, 5B, 6BVery soft and very black
7BSoftest
Out of the above 18 grades of pencils, following grades are used in engineering drawings.
Grade of PencilUsed to Draw
3HConstruction lines
2HDimension lines, center lines, sectional lines, hidden lines
HObject lines, lettering
HBDimensioning, boundary lines
Grades of Pencil

Eraser

Eraser is used to remove the lines or spots which drawn by mistake or with wrong measurements. The eraser used should be of good quality and soft. It should not damage the paper while erasing.
Eraser

Paper Holders

When the drawing sheet is placed on the board it may not be in fixed position. To fix the drawing sheet to the board paper holders are used.
Generally used paper holders are thumb pins, spring clips, stick tapes etc. Care should be taken while removing the clips or tapes otherwise the sheet may tore.
Paper Holders

Comments

Carpet Nashville said…
Another critical issue to bear in mind is the scale of your room. You want to make certain that the ground you select is the proper length for the room.
7 November 2022 at 05:24
Post a Comment

Popular posts from this blog

40+ Construction Tools List with Images for Building Construction

Image
Construction tools list for building construction works such as concrete, brick masonry, leveling, wood works, floor works, slab works, brick laying, plastering etc. is provided. Every construction tool is necessary to achieve good results in the whole project. Along with these tools, the workers should also use some safety tools to prevent them from the unexpected accidents. Construction Tools List for Building Construction Some important construction tools and their uses are listed below: Bolster Boning rod Brick hammer Bump cutter/screed Chisel Circular saw Concrete mixer Cordless drill Crowbar Digging bar End frames Float Gloves Hand saw Helmet Hoe Iron pan Jack plane Ladder Line and pins Mason’s square Measuring box Measuring tape Measuring wheel Pick axe Plumb bob Plumb rule Polishers Putty knife Rammer Rubber Boots Safety glasses Safety helmet Sand screen machine Scratchers Sledge hammer Spade Spirit level Straight edge brushes Til...
Read more

Building Materials properties and their Importance in Construction

Image
Building materials or construction materials are the major requirement in this modern age of technology. There are many types of building materials used for different construction works. Properties of Building Materials For a material to be considered as building material, it should have required engineering properties suitable for construction works. These properties of building materials are responsible for its quality and capacity and helps to decide applications of these material. Such properties of building materials are categorized as follows. Physical properties Mechanical properties Chemical properties Electrical properties Magnetic properties Thermal properties Physical Properties of Building Materials These are the properties required to estimate the quality and condition of the material without any external force. The physical properties of engineering materials are as follows. Bulk density Porosity Durability Density Density index Specific gravity ...
Read more

How to Prevent Errors During Setting Out Building Plan on Ground?

Image
Setting out building plan on ground is one of the most significant steps in building constructions and any errors at this stage would cause considerable problems, if it is not tackled immediately. Errors During Setting Out Building Plan on Ground There are different types of errors that might be made when a structure is set out for example gross errors, systematic errors and random errors. These errors should be prevented and there are some measures to tackle these issues. These measures will be discussed in the following sections. Fig.1: Setting Out of Building Plan on Ground Fig.2: Setting Out Building Plan on Ground How to Prevent Errors During Setting Out of Building? Following are the different types of control that should be carried out to prevent any errors during setting out building plan on ground: Good practice in office On site control Equipment and staff Checks Marking the ground Use of grid offset Good Practice in Office To successfully set...
Read more

Factors Affecting Selection of Foundation for Buildings?

Image
Factors which affect selection of foundation for a building can be many from the soil conditions to the type of structure and loads from the building. All the factors are considered during selection of foundation for durable building construction. Factors Affecting Selection of Foundation Following are the factors which affect the selection of suitable foundations for building construction: Loads from building Type of soil Type of structures in neighborhood Type of foundations 1. Loads from Building The first factor considered is loads from building on the foundation. This load is a combination of dead load and imposed loads on the buildings. Other loads such as wind loads, earthquake loads, snow loads etc. are also considered based on location. The quantity of loads depends on the type of structure, number of floors and material of construction. As the number of floors increases, the dead load and imposed loads also increase. Choice of material for construction su...
Read more

Ceiling types used in Building Construction and their Applications

Image
Various types of ceiling are used in building construction. Applications, aesthetics, advantages and disadvantages of these types of ceilings are discussed in this article. The ceiling of a building form one of the most important structural elements it terms of functionality as well as creativity which in turn bring good aesthetics to the building interior. This document would help you understand ceilings that in turn would help you understand the most suitable options while undertaking either repair or renovation work of our building interior. The ceiling gains a definition, ” A part of a building which encloses and is exposed overhead in a room, protected shaft or circulation space.” It helps us to create an enclosure and separation between spaces. They provide perfect lighting in the room by controlling diffusion of light. It also controls the sound around a room by making the room sound proof. It, therefore, stops the passage of sound between the rooms. Now ceiling also po...
Read more

HOW TO DETERMINE DEPTH OF FOUNDATION

Image
Many factors affects the determination of depth of foundation. Calculation for foundation depth is done based on type of soil, ground water table, loads from structure, bearing capacity of soil and other factors. General factors to be considered for determining depth of foundation are: 1. Load applied from structure to the foundation 2. Bearing capacity of soil 3. Depth of water level below the ground surface 4. Types of soil and depth of layers in case of layered soil 5. Depth of adjacent foundation The minimum depth of foundation should be considered to ensure that the soil is having the required safe bearing capacity as assumed in the design. However, it is advised to carry out soil investigation before deciding on depth of foundation. Soil investigation report will suggest the foundation depth based on the type of structure, soil properties, depth of water table, and all other variable that should be considered. Soil investigation report provides bearing capacity of ...
Read more

WHAT IS VOLUME BATCHING OF CONCRETE AND HOW IT IS DONE IN FIELD?

Image
WHAT IS VOLUME BATCHING OF CONCRETE? Batching of concrete means measuring different ingredients of concrete (i.e. cement, sand, coarse aggregate and water) before mixing it. When this measurement is done on the basis of volume, we call it  Volume Batching . Below are mentioned some of important points to remember before adopting volume batching method in field. Volume batching is not a good method for measuring concrete materials. It is not applicable in case of reinforced concrete structure. This method of concrete batching may not be economical. It can be only used for unimportant concrete or for small concrete works. HOW VOLUME BATCHING IS DONE IN FIELD? Before batching concrete ingredients in terms of volume, we need to know two things. What is the relative proportion of concrete ingredients in terms of volume? What is the water-cement ratio? After knowing these two things you can proceed to batch concrete ingredients in field. The table shown below ca...
Read more

Construction Project Management Softwares

Image
Construction PM Software A new wave of web and cloud apps are streamlining communication, simplifying document management, and improving efficiency in construction management.  Here are some of top construction management tools: Smartsheet Smartsheet  is a spreadsheet-inspired work management tool with robust collaboration and communication features. With pre-built construction templates, it’s easy to create a timeline, track progress, manage documents, and organize the details. Gantt charts are automatically created and auto-adjust every time a change is made, so you can share the most up-to-date timeline with team members or stakeholders. You can upload files from your computer, Google Drive, Box, Dropbox, Evernote, or add a web URL, creating a central repository for all project documentation and contracts. Team members can have discussions directly in the sheet and set reminders and alerts, so everyone is on the same page. And lastly, Smartsheet inte...
Read more

Methods of underpinning, Procedure and Applications in Foundation Strengthening

Image
Underpinning is a method for repair and strengthening of building foundations. Underpinning methods, procedures and their applications in strengthening of different types of foundations is discussed in this article. There are situations where a failure in foundation or footing happens unexpectedly after the completion of whole structure (both sub and superstructure). Under such emergency situation, a remedial method has to be suggested to regain the structural stability. The  method of underpinning  help to strengthen the foundation of an existing building or any other infrastructure. These involve installation of permanent or temporary support to an already held foundation so that additional depth and bearing capacity is achieved. Selection of Underpinning Methods Underpinning methods are selected based on age of structure and types of works involved. Structure categories based on its age: Ancient Structures :Age greater than 150 years Recent Structures : Age ...
Read more

Methods for Calculating Cost of Engineering Consultant Services

Image
here are several methods by which calculation of engineering consultant services cost can be carried out in construction. It is possible to employ various charging approach at different phase of the consultant services. The application of each method or combination of methods is dependent on nature, scope and complexity of the required engineering services. In this article, these charging consulting services are discussed. Following are the topics discussed for calculating cost of engineering services or consulting services in construction: What are the factors that affect the engineering service cost? Methods for charging engineering services What are the Factors that affect the Engineering Service Cost in Construction? There are various factors that control the cost of engineering services required for a specific project. These factors are outlined below: The conditions at project site. Degree of danger that may be encountered and exposure possibility. System of pr...
Read more