What is the first thing you look at on a drawing? The drawing title. This week for “Standards Tuesday” we will be talking about the drawing titles as there are described in ASME Y14.100. Since one the very first things anybody looks at on a drawing is the title, I figured this is the best place to start. I would bet that you were not aware that there was a procedure for drawing titles per ASME standards. Judging by some of the titles I have seen in my career, it seems that no one is aware of these procedures. Section 5 of ASME Y14.100 lays out the procedures for creating titles for engineering drawings and the items they describe. There is an additional section in the appendix that describes titles for non-commercial applications.
Below are some basic rules, per ASME Y14.100, to consider when creating a item or drawing title:
1. “The title shall be as brief as possible, describe the item, and distinguish between similar items.” Each title should have a basic name that describes the drawing or item with as few words as possible. I notice some users tend to want to tell a story with the drawing title. Don’t try to get too descriptive, leave that up to the drawing itself.
2. “The title shall consist of a noun or noun phrase (basic name). Modifiers may be used to distinguish between items with the same basic name.” A modifier is a single word or phrase used to better describe the concept created by the basic name. For example in the title MOUNTING PLATE, LEFT; the basic name MOUNTING PLATE describes the item but the assembly contains two mounting plates. Each plate will be further described as either being LEFT or RIGHT, so that there is no confusion. Additional modifiers can be used to further describe the item or drawing if necessary. Do not use the words “OR” and “FOR” as modifiers in your titles.
3. “The noun or noun phrase establishes the basic concept of an item.” When a single word doesn’t not adequately describe an item, use a combination of words or a phrase. In the example above PLATE by itself does not make a good description, MOUNTING PLATE better describes the item. The noun or noun phrase is used to describe the item or how the item is used. Do not include how the item is manufactured or the item material in the the basic name.
4. “The noun or noun phrase shall be used in singular form..” Items that only exist in plural forms such as gloves and tongs are the exception to this rule. Also, single items that exist in multiple instances on the same drawing may be described in the plural form such as fuses.
5. “An ambiguous noun is not used alone, but may be used as part of a noun phrase.” Ambiguous nouns are words that do not directly apply to the item itself. Words such as assembly, schematic, sub-assembly, box, plate, etc.. are considered to be ambiguous and should not be used by themselves but only as a portion of a noun phrase such as WIDGET ASSEMBLY instead of ASSEMBLY, WIDGET.
6. “When an item is neither container nor material, but its name involves the use of a noun that ordinarily designates a container or material, a noun phrase shall be used as the basic name.” In other words, a junction box is not a box and should not be described as such in the title. Instead of making the title BOX, JUNCTION the proper way to title the item is just JUNCTION BOX.
7. “Abbreviations should be avoided.” This rule is pretty straight forward.If abbreviations are required , however, then approved abbreviations per ASME Y14.28a should be used.
8. “The title shall be consistent with the title of the next assembly.” Child parts and sub-assemblies should be consistent with the parent assembly.
9. “When titles are used on continuation sheets, the title shall be the same on each sheet.” In SolidWorks, this should not be an issue if you properly link the drawing title to a custom property.
10. “Reference to major assemblies or end items shall not be used except when necessary to differentiate similar items.” A good rule of thumb is to only include the name of the immediate parent assembly in the title if necessary. If you are titling a drawing or item that is 5 levels deep, do not include the top level assembly name in the title only the parent sub-assembly name.
11. “Nonpart drawings, such as schematic diagrams, shall include the drawing type as part of the title.” Schematics, wiring diagrams, flow charts and such should include what the drawing type is in the title. This makes finding the supporting documents easier to find.
I hope you will find this entry helpful in creating your drawing titles.As with all standards, your companies usage may differ from what is describe. However, I think you will find that the more you follow the rules describe above the better you documentation system will run, especially as your system grows. In the weeks that following I will be discussing more aspects of a drawing as described in ASME procedures.