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Mechanical Drawings Terms
Print Reading: a print reading is a document used to communicate the specifics of a machine process or device. Print reading involves the ability to interpret diagrams, geometric shapes and line patterns including circles, arcs, diamonds, triangles, microgrips, etc.
Mechanical Drawing Types:
Mechanical drawings can be classified into four main types: Pictorial drawings, Orthographic Projections, Sectional Views and Auxiliary Views.
1. Pictorial Drawings: Pictorial drawings are drawings that display the overall look of an object from a top or an isometric or oblique view. It is a representation of a 3-D object, in which all parallel lines appear to be curved since they are being presented from an angle.
2. Orthographic Projections: Orthographic Projections are also known as technical drawings, which display all sides of the object. They display views in two dimensions, utilizing all six faces of the object.
3. Sectional Views: Sectional views are a type of orthographic projection that displays “cutaway” sections of an object in order to show detail. They are commonly used to explain the design and parts of a mechanism.
4. Auxiliary Views: Auxiliary views are orthographic projections that display an object from an angle not visible in other projections. They are sometimes called “secondary” views.
Dimensioning Terms:
Dimensioning describes a method of measuring the magnitude of an object and recording its dimensions. It usually involves drawing a part and providing respective numbers, symbols, letters and notes to define the size and shape of the object accurately.
• Tolerance: Tolerance is the amount of Deviation from a specified dimension that is accepted.
• Datum: Datum is a point, line or plane from which measurements are taken from or referred to.
• Leading Edge: The Leading Edge is the visible edge of an object or drawing.
• Size: Size is the numerical value, typically in millimeters or inches, that defines an object’s dimension.
• Linear Dimension: Linear Dimensions define the length or width of an object.
• Chain Dimension: Chain Dimensions use ‘Initial Letters’ to differentiate between multiple dimensions of the same kind.
• Arc Dimension: Arc Dimensions are used to describe the radius of arcs or circles.
• Angular Dimension: Angular Dimension is used to describe the angle between two lines or planes.
• Dimension Line: A Dimension Line is a line on which the size of an object is indicated.
• Leader Line: A Leader Line is a short line used to connect the dimension line to the inspected object.
• Extension Line: Extension Lines extend the dimension line beyond the object, towards the dimension text.
• Dimension Text: Dimension Text is a numerical value that indicates the size of the object.
• Champion Line: Champion Lines are used in work drawings to denote where an object should be cut or drilled to the exact size.
Welding Terms:
• Weld Symbol: A weld symbol is a graphical representation used to indicate the type of weld, size of weld and other welding information.
• Groove Weld: A Groove Weld is a type of weld that penetrates and unites two parts along the surfaces of two or more adjoining members.
• Plug Weld: A Plug Weld is a type of weld used to join two or more plates in which one space is completely cut out.
• Slot Weld: A Slot Weld is a type of weld that joins two or more plates in which one space is partially cut out.
• Edge Weld: An Edge Weld is a type of weld used to join two or more plates in which one space is left the same.
• Tack Weld: A Tack Weld is a type of weld used to temporarily hold two or more parts together while they are being welded.
• Fillet Weld: A Fillet Weld is a type of weld that joins two parts by creating an angled connection across the gap of the two faces.
• Lap Joint: A Lap Joint is a type of weld that unites two parts by overlapping one over the other.
• Butt Joint: A Butt Joint is a type of weld that unites two parts by having them end up opposite each other, with either one of them being flush with the other.
• Spot Weld: A Spot Weld is a type of weld used to permanently fasten two or more steel parts together by fusing them together at multiple points.
