CBSE Class 12 Syllabus Engineering Drawing (2025-26) | Latest Edition

THEORY

Unit I: Isometric Projection of Solids [40 Periods]

(i) Construction of isometric scale showing main divisions of 10mm and smaller divisions of 1mm, also showing the leading angles. Drawing helping view/s such as triangles, pentagon, hexagon, etc., using isometric scale.
(ii) Isometric projection (drawn to isometric scale) of solids such as cube; regular prisms and pyramids (triangular, square, pentagonal and hexagonal); cone; cylinder; sphere; hemisphere. The axis and the base side of the solid should be either perpendicular to HP/VP or parallel to HP and VP. (Indicate the direction of viewing).
(ii) Combination of any two above mentioned solids keeping the base side parallel or perpendicular to HP/VP and placed centrally together (Axis of both the solids should not be given parallel to HP).

Note: Hidden lines are not required in isometric projection.

Unit II: Machine Drawing (as per SP46: 2003) [75 Periods]

A. Drawing of machine parts

(i) Drawing to full size scale with instruments. [25 Periods] (Internal choice will be given between any two of the following). Introduction of threads: Standard profiles of screw threads – Square, Knuckle, B.S.W., Metric (external and internal); Bolts – Square head, Hexagonal head; Nuts – Square head, Hexagonal head; Plain washer; combination of nut and bolt with or without washer for assembling two parts together.
(ii) Free-hand sketches
(Internal choice will be given between any two of the following).
Conventional representation of external and internal threads; Types of studs – Plain stud, Square-neck stud, Collar stud; Types of rivets – Snap head, Pan head (without tapered neck), Flat head, 600 countersunk flat head.

B. Assembly drawings and Dis-Assembly drawings

(Internal choice will be given between an Assembly drawing and a Dis-Assembly drawing). [50 periods]

1.Bearings
(i) Open-Bearing
(ii) Bush- Bearing

2.Rod-Joints
(i) Cotter-joints for round-rods (Sleeve and cotter joint)
(ii) Cotter-joints for square rods (Gib and cotter-joint)

3.Tie-rod and Pipe-joint
(i) Turnbuckle
(ii) Flange pipe joint

Note:

(i) In all Assembly drawings, half sectional front view will be asked. Side/End view or Top View/Plan will be drawn without section.
(ii) In all Dis-assembly drawings, only two orthographic views (one of the two views may be half in section or full in section) will be asked of any two parts only.
(iii) a. In all sectional views, hidden lines/ edges are not to be shown.
      b. In all full views, hidden/edges are to be shown.

PRACTICALS [45 Periods]

(i) To perform the following tasks (for One only) from the given views of the prescribed ten machine blocks in ANNEXURE-I.

Value-Points
a. Copy the given views [1 Marks]
b. Drawing the missing view with hidden lines  [2 Marks]
c. Sketching the Isometric view without hidden edges  [5 Marks]
d. To make the machine block of the above in three dimensions. [7 Marks] (Not to scale but approximately proportionately drawn with Any medium i.e. thermocol, soap-cake,

(ii) plasticine, clay, wax, orchsis (available with florists), etc.
Computer Aided Design (CAD) – Project [10 Marks] Project file to be submitted on the simple solids (Prism, Pyramids and Frustums of equilateral triangle, square, pentagon and hexagon) or machine blocks as prescribed in part-I by using the CAD software.

(ii) a. Sessional work relating to machine blocks as prescribed.  [3 Marks]
     b. Viva-voce based on part-I and part-II [2 Marks]  Total Marks 30

ACTIVITY

Industrial Visits (Two) to any industry/ manufacturing plant to acquaint the students with the present – day methods & technology for better conceptual understanding can be done by virtual tour of the factory/plant.