Technical drawing is a universal language used for communication among technological professionals. The professionals that use technical drawing are Architects, Engineers, surveyors, technicians, technologists, draughtsman, designers etc.
Professionals and students of technical drawing need the required instruments and materials to make good drawings because technical drawing involves the use of symbols, lines, measurements, etc. to represent ideas, knowledge, imagination (design) and information to others.
Drawing instruments: The drawing instruments necessary for technical drawing are the tools/equipment that makes drawing possible.
The following are the necessary drawing instruments:
- Drawing board
- Set of drawing instruments
- Set squares
- French curves
- Scale rules
- Metric rules
- Drawing board: This is a wooden platform on which drawing paper is fixed in readiness for drawing. There are 2 types where are: Full imperial and half imperial. Half imperial drawing is the type of drawing board used by students.
- Tee square: The tee square is a T-shaped instrument used for drawing horizontal lines, setting drawing papers on the drawing board at angle 90. It is also used to aid set-squares to function as required. It is made of wood, plastic and metal.
- Set of drawing instruments: The set of drawing instruments include:
- A pair of compass: It is used for picking and transferring dimensions from the rule to the drawing paper.
- A pair of divider: It is used for picking and transferring dimensions from the rule to the drawing paper.
iii. A bow compass: It is used to draw circle of large dimensions.
- Set Squares: They are available in plastic (acrylic) and wood. They are used with the squares to draw angle, vertical and diagonal lines. The 2 types are 30o x 60o and 45o x 45o set square.
- Protractor: It is made from plastic material marked into angles from 0o to 180o. It is used for measuring angles.
- French curves: They are transparent plastic material of different shapes, sizes and curves. They are used to draw curves that are not circle, semi-circle or arc.
- Scale rule: It is a triangular shaped instrument. It is graduated on each side, with scale ratios. It is used to reduce and enlarge the sizes of object on drawing paper.
- Metric rules: They are used to measure straight lines, distances, and make drawings to required sizes. They are available in metals, plastics and wood.
- Templates: They are used to draw various architectural and geometrical shapes and symbols. They are also used for lettering.
- Sharpeners: They are used to sharpen pencil points to conical, shape and maintain the sharpness of pencils for good draughtmanship.
These are consumable items used for technical drawing. They are consumable because they cannot be reused after being used.
The following are the necessary drawing materials.
- Drawing paper
- Emery clothes/Glass paper.
- Adhesive paper.
- Drawing pencil
- Drawing paper: These are white paper on which drawing is done. The mostly used sizes are A2 to A4.
- Erasers: Erasers are rubber materials used to clean dirt and errors made. A good eraser should be able to clean errors without tearing the paper.
- Handkerchief: It is a small clothing material used for cleaning and dusting.
- Emery clothes/Glass paper: They are materials used to maintain the sharpness of pencil at all times.
- Adhesive paper: It is commonly called callotape. It is used to fix drawing paper on the drawing board.
- Drawing pencil: the drawing pencil is used for preparing the drawing on the drawing paper.
|Grades of Pencil||Hardness|
|6H, 5H, 4H||Extremely hard|
|B||Moderately Soft and Black|
|2B||Soft and black|
|3B||Very soft and black|
|4B, 5B, 6B||Very soft and very black|
Care in Handling and Maintaining Drawing Instruments and materials.
- Do not use the drawing board for any other purposes than for drawing.
- The surface of the drawing board must be in good condition. Do not use sharp objects like knife to cut on it.
- Always clean the drawing board before use.
- Cover drawing board surface with paper or cardboard after use.
- Tee Square should not be used as walking stick
- The blade must be straight at angle 900 to the stock
- Always clean the tee square before using it.
Set of drawing Instruments
- They must not be used for other purposes other than their primary functions.
- Do not use compass and divider to hold paper.
- Do not use compass and divider to fight
Set square, protractor, French curve and scale rule/ metric rule
- Do not place heavy load on them to prevent breakage.
- Do not use sharp objects to cut on their edges.
- Store them in a safe place.
- Drawing pencil should be kept in a pencil packet after use.
- Pencil points must be pointed.
All other instruments should be stored in a cupboard to prevent damage.