Glossary
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Tack weld: Small spaced welds used to hold edges of an object together.

 



Take: 'Take' is another way of saying 'subtract'. '9 take 4' is the same as 'subtract 4 from 9'.

 



Tangent: A tangent is a straight line which intersects a curve. It is always at right angles to the radius (of a circle).

In trigonometry, a tangent is one of the basic functions (along with sine and cosine). In a right angled triangle, the tangent is the ratio of the length of the adjacent side to the length of the opposite side.

 



Tangent point: A tangent point (point of tangency) is the exact point where a straight line intersects with a curve or circle.

The tangent points are the marks drawn on each axis when drawing a radius.

 



Taper: Taper is the way that a shape gradually narrows at one end.

 



Technical drawing: Technical drawing is the technique used to create accurate representations of objects for engineering drawings.

 



Templates: A template is a pattern made from paper or a thin metal plate which is used as a guide to make a shape accurately, and can be used repeatedly.

 



Third angle projection: In third angle projection

Third angle projection is a method of creating a 2D drawing of a 3D object that is recommended by the Australian Standard 1100 Part 101.

 



Three dimensional: Three dimensional engineering drawings show height, width and depth.

 



Three dimensions: One simple explanation or proof that there are 'three dimensions' is that there are three directions of free movement:

An example of the use of three dimensions is that to pinpoint an exact location on earth, three coordinates are needed longitude, latitude, and elevation above sea level.

When describing the size of an object (or a space), three measurements are used:

In mathematics, three independent coordinates are needed to specify any point in a given space. These points are traditionally labelled 'x', 'y', and 'z'.

 



Tolerance: Tolerance is the allowed deviation for a specified dimension. How much deviation is acceptable is different for each type of job. The deviation or error is displayed as ± measurement.

 



Tolerance error: A tolerance error is the difference between the dimension on the engineering drawing and the measurement of the manufactured component. It is normal to have an error because it is impossible to make a component that is absolutely perfect.

 



Toleranced dimension: The toleranced dimension is the final measurement of the manufactured component. The toleranced dimension is a combination of the dimension and a tolerance error.

 



Transition: Transition is the term given to a shape which changes from one form to another, for example, square to round.

 



Transition shapes: Transition shapes are shapes that change eg from square to round or rectangular to round.

 



Transpose: To transpose is to put something into a different place.

 



Transposition of formula: Solving mathematical problems often requires the manipulation of formula. This is called transposing. There is one simple rule.

Whatever is done to one side of the formula must be done to the other!

 



Triangle: A triangle is a three (straight) sided figure.

Triangles can be classified according to the size of the largest internal angle.

Triangles can also be classified according to the relative lengths of the sides:

 



Triangulated layout patterns: Triangulated layout patterns are patterns developed using the triangulation method.

 



Triangulation: Triangulation is a geometric development process used to find the true length of a surface that cannot be seen as a true length on a drawing.

 



Trigonometry: Trigonometry deals with calculations based on the relationships between the sides and the angles of triangles, that is, the trigonometric functions. Three basic trigonometric functions are:

There are many applications of trigonometry. For example, the technique of triangulation is used in astronomy to measure the distance to nearby stars, in geography to measure distances between landmarks, and in satellite navigation systems. It is also applied in metal fabrication to make small and large components.

 



True length: The actual length of any given line or surface. Sometimes the true length of surfaces on a 3D object are not obvious on a 2D drawing.

 



True length development lines: True length lines are the actual true lengths of any given surface and are established using the geometric development process called triangulation.

 



True proportion: True proportion is the actual proportion. The measurements of an object drawn in true proportion are directly related to the those of the real object. There is no distortion.

 



Truncate: To cut the top of a shape along a plane that is not parallel to the base .

 



Truncated cylinder: Truncated cylinder that has either the top or bottom cut at an angle.

 



Truncation: Truncations are cuts at an angle other than 90°.

 



Twist: Twist refers to pressing or rolling where the edges become misaligned.

 



Two dimensional: Two dimensional engineering drawings show height and width.