Projection lines or extension lines are usually drawn using:
Continuous thin line
Engineering drawing uses a fixed set of line conventions (as per the standard line types) so that anyone reading the drawing understands each feature without confusion.
Projection lines, also called extension lines, are the light lines that project outward from a feature to show exactly which points a dimension is measuring between.
Because their only role is to guide the eye to the dimension, they must be faint and unobtrusive so they never look like part of the actual object.
For this reason they are drawn as a continuous thin line, the same light quality used for dimension lines, hatching, and leader lines.
A continuous thick line (option 3) is reserved for visible outlines and edges of the object, so using it for projection lines would make them look like real edges.
A dashed thin line (option 4) means a hidden edge, and a chain thick line (option 1) is used for cutting planes, so neither convention fits an extension line.
Hence, the answer is Continuous thin line.
Similar Questions
Match the following, according to lettering and numbering (uppercase lettering) as per
BIS SP: 46-2003.
Width (W) Capital letters
(A) 5 (I) W
(B) 6 (II) A, M, Q, V, X, Y
(C) 7 (III) B, D, G, H, K, N, O, P, R, S, T, U and Z
(D) 9 (IV) C, E, F, LWhich of the following statements is/are true about Non-Functional Dimensions (NF) in engineering drawing?
Statement 1: Non-functional Dimensions are shown without limits, as they do not affect the functionality of the component or space.
Statement 2: Non-Functional Dimensions are typically used for reference purposes only, and do not impact the assembly or performance of the component or space.Match the following designations of sheets with their respective trimmed sizes in length and breadth.
Designation Trimmed Size
A) A0 P) 297 × 420
B) A1 Q) 420 × 594
C) A2 R) 594 × 841
D) A3 S) 841 × 1189engineering drawings recommend(s) 20 mm wide margins for sheet sizes AO and A1 in
In a project involving the design of a pipeline for a building, which technical drawings would need to be referenced together?
Match the correct length and breadth of the Trimmed sizes of sheets.
Designation
A. A0
B. A1
C. A2
D. A3
Trimmed size
P. 297 × 420
Q. 420× 594
R. 594 × 841
S. 841 × 1189
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A ________ diagram is a schematic drawing that shows the relationships in a system, using simple shapes for the entities.
The notation 2 × Ø6 means______.
Important Questions from Engineering Drawing
What is a polygon with 12 sides called?
Wiring diagrams, circuit diagrams and electrical installation drawings are examples of which of the following types of engineering drawings?
Which of the following is NOT an element of dimensioning ?
Which of the following drawing instruments is used to draw smooth curves/arcs?
_______ is a dimension that is essential to the functioning of the component or space that is generally shown with limits.
