N d bhatt and v m panchal, engineering drawing, 43rd edition, charator publishing house, 2001 4 4. Swing the pencil back and forth between the points, barely touching the paper until the direction is clearly established. Weight refers to line thickness or width.
Extension Line In Engineering Drawing
They contain all the information needed to
(lecture in hindi) in this video, you can learn in deep about how to use dimension line, extension line, and leader command in engineering drawings.1.) dimen.
When extension lines cross object lines or other extension lines, they are not broken. The lines are defined as follows: Dimension and extension line placement 1. Dimension lines should never coincide with any object line or center line of the drawing.
The line is perpendicular to the dimension line used to show a feature d.
The line shows hidden features of the figure Used to indicate the size a geometric feature. Spot the beginning and end points. Using the alphabet of lines construction line.
Generally, there are 11 basic types of lines.
The line shows dimensions not used in fabrication c. Overdraw with longer heavier strokes x x x x 1) x 6 2) x 3) Dimension lines should never cross. What are the 4 types of sketching lines?
It extends by about 3 mm beyond the dimension line.
Detail dimensions should line up in chain fashion. Longer dimensions should be placed outside all intermediate dimensions so that dimension lines will not cross extension lines. What is the significance of an extension line in an engineering drawing? Extension lines continue or extend from the surface of the object and establish the size of the dimension.
Used to extend the edge, face or corner of a geometric feature.
In machine drawing, all unit marks should be omitted, except when necessary for clarity; An extension line is a thin, dark, solid line that extends from a point on the drawing to which a dimension refers. Thin line with arrow or dot. The line shows the limits of a dimension b.
Dots are placed on faces or surfaces.
The dimension line meets the extension lines at right angles, except in special cases. This type is also used to draw outlines of adjacent and revolved sections. This line is used mainly in sketching, which is a freehand drawing technique. (a) extension lines are used to indicate the extension of an edge or point to a location outside the part outline.
An engineering drawing is a subcategory of technical drawings.
Working drawings are the set of technical drawings used during the manufacturing phase of a product. This line is used to draw all the edges of the object. They do not touch the object lines and extend slightly past the dimension line. They are drawn for constructing figures.
Extension lines should never be shortened.
When extension lines cross or are close to arrowheads, they are broken for the arrowhead. Extension lines provide a means of displaying a measurement without placing the dimension on. An engineering (or technical) drawing is a graphical representation of a part, assembly, system, or structure and it can be produced using freehand, mechanical tools, or computer methods. Start at one end , make series of very light, short line (2.5cm), slightly overlapping, moving toward the end point 4.
Used to indicate the size or location of the geometric feature.
For example, 1 reamer or 1mm drill. Always place shorter dimensions nearest to the object lines. (b) dimension lines show the direction and extent of dimension. Since technical drawings are made of lines, it is logical that the first step in learning to “read” a drawing is to learn the meaning of each kind of line.
Extension lines extension lines should not cross dimension lines, and should avoid crossing other extension lines whenever possible.
The purpose is to convey all the information necessary for manufacturing a product or a part. The extension lines for dimensioning should run from the outlines without leaving a gap and extend beyond the dimension lines. Orient paper for smooth movement of your hand 3. A gap of about 1.5 mm should be left where the extension line would join the object outline.
The line shows visible features of the figure e.
Extension lines on a drawing are fine, dark, solid lines that extend outward from a point on a drawing to which a dimension refers. (c) leader lines are used to direct an expression, in note form, to the intended place on the drawing. Engineering drawings use standardised language and symbols. However, extension lines may cross each other.
T e french, c j vierck and r j foster, graphic science and design, 4th edition, mcgraw hill, 1984 5.
