Engineering Graphics

Download CBSE class 12 Engineerings Graphics study material in PDF format. MyCBSEguide provides solved papers, board question papers, revision notes and NCERT solutions for CBSE class 12 Engineerings Graphics. The topics included are Isometric Projection, Machine Drawing, Bearings, Rod Joints, Tie-rod and pipe joints, Shaft Couplings, Pulleys.

Unit I: Isometric Projection of Solids
(i) Construction of isometric scale showing main divisions of 10mm and smaller divisions of1mm, also showing the leading angles. Drawing helping view/s such as triangles, pentagon, hexagon, etc., using isometric scale.
(ii) Isometric projections (drawn to isometric scale) of solids such as cube, regular prism and pyramids (triangular, square, pentagonal and hexagonal), cone, cylinder, sphere, hemisphere, frustum of right regular pyramids (triangular, square, pentagonal, hexagonal) and cone, when they are cut by a plane parallel to the base. 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)
(iii) Combination of two solids (except "frustum" of Pyramids and Cone) 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: (1) Question on frustum will be asked in vertical position only.
(2) Hidden lines are not required in isometric projection.

Unit II: Machine Drawing (as per SP46: 2003) (118 Periods)
A. Drawing of machine parts
(i) Drawing to full size scale with instruments.
(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, Hexagonal, Tee and Hook);
Nuts: (Square and Hexagonal), Plain washer, combination of nut and bolt with or without washer for assembling two parts together, Single riveted lap joint with standard dimensions.

(ii) Free-hand sketches
(Internal choice will be given between any two of the following).
Conventional representation of external and internal threads; studs (plain, square-neck and collar), screws (round-head, cheese-head, 900 flat counter sunk-head, hexagonal socket head and grub-screw). Types of rivets:- snap head, pan head-without tapered neck, flat head and 600 countersunk flat head. Types of sunk-keys (rectangular taper, woodruff and double-head feather key with gib head on both ends).

B. Assembly drawings and Dis-Assembly drawings (Internal choice will be given between an Assembly drawing and a Dis-Assembly drawing).

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

2. Rod-Joints
(i) Cotter-joints for circular-rods (socket and spigot joint)
(ii) Cotter-joints for round-rods (sleeve and cotter joint)
(iii) Cotter-joints for square rods (Gib and cotter-joint)

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

4. Couplings
(i) Unprotected Flange Coupling (having socket and spigot arrangement)
(ii) Protected Flange Coupling

5. Pulleys
(i) Solid cast iron pulley-(upto 200mm diameter) having solid web