T-square
Encyclopedia
A T-square is a technical drawing instrument
used by draftsmen
primarily as a guide for drawing horizontal lines on a drafting table. It may also guide a triangle to draw vertical or diagonal lines. Its name comes from the general shape of the instrument where the horizontal member of the T slides on the side of the drafting table. T-squares come in varying sizes, common lengths being 18"
, 24", 30", 36" and 42".
T-squares are also used to measure and cut drywall
. Drywall T-squares are typically made of aluminium
and have a 48-inch
(1,220 mm) long tongue
.
Higher-end table saw
s are often equipped with T-square fence
s. These table saw fences are attached to a rail
only on the front side of the table unlike traditional fences which clamp to both the front and the rear of the table.
The top of the T-square hangs off of the drafting table and is called the head; the blade is the part that stays on the drafting table. The T-square usually has a transparent
edge made of plastic
which should be free of nicks and cracks in order to provide smooth, straight lines.
T-squares have been used to cut drawings created by draftsmen since the inception of the instrument. This is inadvisable: One might cut the T-square in the process, damaging the straight edge and rendering the T-square useless. However, extremely advisable when using a metal T-square.
Measuring instrument
In the physical sciences, quality assurance, and engineering, measurement is the activity of obtaining and comparing physical quantities of real-world objects and events. Established standard objects and events are used as units, and the process of measurement gives a number relating the item...
used by draftsmen
Technical drawing
Technical drawing, also known as drafting or draughting, is the act and discipline of composing plans that visually communicate how something functions or has to be constructed.Drafting is the language of industry....
primarily as a guide for drawing horizontal lines on a drafting table. It may also guide a triangle to draw vertical or diagonal lines. Its name comes from the general shape of the instrument where the horizontal member of the T slides on the side of the drafting table. T-squares come in varying sizes, common lengths being 18"
Inch
An inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot...
, 24", 30", 36" and 42".
T-squares are also used to measure and cut drywall
Drywall
Drywall, also known as plasterboard, wallboard or gypsum board is a panel made of gypsum plaster pressed between two thick sheets of paper...
. Drywall T-squares are typically made of aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
and have a 48-inch
Inch
An inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot...
(1,220 mm) long tongue
Tongue
The tongue is a muscular hydrostat on the floors of the mouths of most vertebrates which manipulates food for mastication. It is the primary organ of taste , as much of the upper surface of the tongue is covered in papillae and taste buds. It is sensitive and kept moist by saliva, and is richly...
.
Higher-end table saw
Table saw
A table saw or sawbench is a woodworking tool consisting of a circular saw blade, mounted on an arbor, that is driven by an electric motor...
s are often equipped with T-square fence
Fence (woodworking)
A fence is a straight edge that is placed parallel to the direction of the cut saw blade. It is rigidly connected to the saw or table. The distance between the surface of the fence and the closest edge of the saw blade dictates the specified width of the cut. Material that is being cut is held...
s. These table saw fences are attached to a rail
Rail
Rail or rails may refer to:Railway transportation* A generic term for railroads, railways, rail transport, and related matters* Rail tracks, or railway lines, the running surface of a railway...
only on the front side of the table unlike traditional fences which clamp to both the front and the rear of the table.
The top of the T-square hangs off of the drafting table and is called the head; the blade is the part that stays on the drafting table. The T-square usually has a transparent
Transparency and translucency
In the field of optics, transparency is the physical property of allowing light to pass through a material; translucency only allows light to pass through diffusely. The opposite property is opacity...
edge made of plastic
Plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
which should be free of nicks and cracks in order to provide smooth, straight lines.
T-squares have been used to cut drawings created by draftsmen since the inception of the instrument. This is inadvisable: One might cut the T-square in the process, damaging the straight edge and rendering the T-square useless. However, extremely advisable when using a metal T-square.