इंजीनियरिंग ड्राइंग में प्रयुक्त रेखायें प्रयुक्त (Lines used in Engineering Drawing) निम्नानुसार हैं -
(1)Outlines (A):वस्तुओं के दृश्य किनारों और सतह की सीमाओं को दर्शाने के लिए खींची गई रेखाओं को रूपरेखा(Outlines) या प्रमुख रेखाएँ(PrincipalLines)कहा जाता है। ये continuous thick or wide lines होती हैं Click to See->(fig-P2).
(2)Margin lines (A): ये continuous thick or wide lines होती हैं जिसके साथ साथ प्रिंटस् काटे जाते हैं Click to See->(fig-P1).
(3) Dimension Lines(B): ये continuous thin lines होती हैं इनके बाहरी सिरों पर तीक्ष्ण तीर चिह्न (pointed arrowheads) जो रूपरेखा, विस्तार या केंद्र रेखाओं touching the (outlines, extension lines or centre lines) को छूते हैं Click to See->(fig-P2).
(4) Extension or projection lines (B): ये भी continuous thin lines होती हैं।
इनका विस्तार आयाम रेखा (dimensionline) से परे लगभग 3mm होता है Click to See->(fig-P2).
(5) Construction lines (B): These lines are drawn for constructing figures.
They are shown in geometrical drawings only. They are continuous thin light lines.
(6) Hatching or section lines (B): These lines are drawn to make the section evident. They are continuous thin lines and are drawn generally at an angle of 45° to the main outline of the section. They are uniformly spaced about 1 mm to 2 mm apart Click to See->(fig-P2).
(7) Leader or pointer lines (B): Leader line is drawn to connect a note with the feature to which it applies. It is a continuous thin line Click to See->(fig-P2).
(8)Border lines (B): Perfectly rectangular working space is determined by drawing the border lines Click to See->(fig-P1). They are continuous thin lines.
(9) Short-Break lines (C): These lines are continuous, thin and wavy. They are drawn freehand and are used to show a short break, or irregular boundaries Click to See->(fig-P3).
(10) Long-break lines (D): These lines are thin ruled lines with short zigzags within them. They are drawn to show long breaks Click to See->(fig-P3).
(11) Hidden or dotted lines (E or F): Interior or hidden edges and surfaces are shown by hidden lines. They are also called dotted lines. They are of medium thickness and made up of short dashes of approximately equal lengths of about 2 mm spaced at equal distances of about 1 mm. When a hidden line meets or intersects another hidden line or an outline, their point of intersection or meeting should be clearly shown Click to See->(fig-P2).
(12) Centre lines (G): Centre lines are drawn to indicate the axes of cylindrical, conical or spherical objects or details, and also to show the centres of circles and arcs. They are thin, long, chain lines composed of alternately long and dot spaced approximately 1 mm apart. The long dashes are about 9 to 12 mm. Centre lines should extend for a short distance beyond the outlines to which they refer.
For the purpose of dimensioning or to correlate the views they may be extended as required. The point of intersection between two centre lines must always be indicated. Locus lines, extreme positions of movable parts and pitch circles are also shown by this type of line Click to See->(fig-P2). and Click to See->(fig-P3).
(13) Cutting-plane lines (H): The location of a cutting plane is shown by this line. It is a long, thin, chain line, thick at ends only Click to See->(fig-P2).
(14) Chain thick (J): These lines are used to indicate special treatment on the surface Click to See->(fig-P3).
(15) Chain thick double-dots (K): This is chain thin double-dot line Click to See->(fig-P3).
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