Drafting symbols, standards and template
When 2D drafting systems first started being used, it made sense to build up libraries of frequently used symbols so they could be be cut and paste onto drawings as required. The simplest of these libraries were just individual drawings which you opened, copied what you needed, then pasted the symbols into the drawing you were working on.
Things got more sophisticated when these libraries were organized into menus, where you could pick the symbol you needed from a drop down list. You didnt need to have a drawing full of symbols loaded into memory. Menu driven systems could also be used with large digitizing tablets, where all the symbols were in plain sight and all you had to do was point to them to build up a schematic diagram.
Most cad systems nowadays use symbol libraries that use software driven symbol generators that dont require a huge library of symbols at all. In these systems, you click on the requirements you want and the software builds the symbols for you. For example welding symbols where you need only select left hand or right hand, size of weld, far side or near side and so on. The nice thing about these systems is that you can go back and edit any symbol if the design needs to be changed
Most of my experience is with SolidWorks and AutoCad and both those packages come with a lot of symbols pre-installed. What follows are instructions to help you find these symbols for yourself
Accessing symbols in AutoCAD
In AutoCad I am fond of using "Tool Palettes" These allow you to have your commonly used symbols located in a box to the left or right of your screen all organized into categories.
If you type "toopalette" a the command line" in AutoCAD it should make the palette window show up similar to the one on the left.
In the picture I have added some electrical blocks to the palette so I can just drag and drop the symbols in whenever I need to build a schematic diagram
To get the symbols into the palette you first need to save each of you symbols as a seperate autocad file and them save them all into a directory
You dont have to confine yourself to symbols either, you can have whole drawings located off to the side if you wish, ready for quick modification
Next, type "ADCENTER" into the command line use the directory tree to locate the directory where the symbols were saved. Right click in the directory area and click "Save as Tool Palette".
Just click through all the default samples found in the palette. Insert them into your drawings and experiement. You may find you dont need to create new symbols at all
Accessing symbols in SolidWorks
In SolidWorks you have quite a lot of library components too. There are free models in Content Central, piping components, unistruts, retaining rings and free models of homer simpson and sponge bob. Some of it is close to hand, but some of the most interesting symbols have to be downloaded.
There is a combination of symbols for SolidWorks drawings as well as complete 3D models such as piping flanges, battery holders and so on
If you are looking for a particular symbol, there are a wide variety of software packages that provide just about any symbol and drafting standard you could imagine.
CADsymbols® CD is the most extensive collection of standard parts and symbols available containing over 30 million symbol drawings and models in 2D/3D view and freely revolving 3D models. CADsymbols CD is perfect for mechanical engineers; mechanical drafters' and non-professionals in the mechanical design arena who want to directly download complex symbols into their drawings instead of create them from scratch. Supports both imperial and metric measurements.