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 set square to draw vertical or diagonal lines. Its name comes from its resemblance to the letter T. T-squares come in varying sizes, common lengths being 18 inches (460 mm), 24 inches (610 mm), 30 inches (760 mm), 36 inches (910 mm) and 42 inches (1 , 100 mm) Ames Lettering Instrument If you have many lines of lettering to do, you will find a lettering instrument, such as the Ames lettering instrument, shown in figure 3-43, view B, quite useful and timeserving.
The top-left section of figure 3-43, view 8, shows how to use this instrument in conjunction with a T square to draw properly spaced horizontal guidelines. You insert the point of your pencil through one of the holes, and the instrument slides along the T square as you move the pencil across the page. The enlarged drawing of the instrument in the lower part of the figure shows the details of how the instrument is used. Notice the three rows of holes in the circular disc of the instrument.
An architect’s scale is a specialized ruler designed to facilitate the drafting and measuring of architectural drawings, such as floor plans and orthographic projections. Because the scale Of such drawings are often smaller than life- size, an architect’s scale features multiple units of length and proportional Engel increments. For accuracy and longevity, the material used should be dimensionally stable and durable. Scales were traditionally made of wood, but today they are usually made of rigid plastic or aluminum. Architect’s scales may be flat with 4 scales, or have a symmetric 3-ebbed cross-section, with 6 scales.
Any scale is called an engineer’s scale and is a tool for measuring distances and transferring measurements at a fixed ratio of length. It is commonly made of plastic,or aluminum and is just over 12 inches (305 mm) long, but with only 12 inches of markings, leaving the ends unmarked 50 that the first and last assuring ticks do not wear off. It is used in making engineering drawings, commonly called blueprints, blue lines or plans in a specific scale, For example, “one-tenth size” would appear on a drawing to indicate a part larger than the drawing on the paper itself.
It is not to be used to measure machined parts to see if they meet specifications. Irregular Curves are useful for drafting and drawing curved and rounded shapes. These professional quality irregular curves are had finished and made of . 060′ thick acrylic. A protractor is a square, circular or semicircular tool, typically made of reentrant plastic or glass, for measuring angles. Most protractors measure angles in degrees (0). Radian-scale protractors measure angles in radians.
They are used for a variety Of mechanical and engineering-related applications, but perhaps the most common use is in geometry lessons in schools. A mechanical pencil (IIS English) or a propelling pencil (UK English) or a pen pencil (Indian is a pencil with a replaceable and mechanically extendable solid pigment core called a lead /led/. The lead is not bonded to the outer casing and can be extended as its point is worn away. The lead is often dad of graphite or a solid pigment. True point pencil is mainly used by Drafts People.
It will sharpen a drafters lead pencil to a tine point. Does NOT sharpen a regular pencil. An eraser (US and Canada) or rubber (elsewhere) is an article of stationery that is used for removing pencil markings, Erasers have a rubbery consistency and are often pink or white. Some pencils have an eraser on one end. Typical erasers are made from synthetic rubber, but more expensive or specialized erasers are vinyl, plastic, or gum-like materials. Cheaper erasers can be made out of synthetic soy- based gum.