350 Appendix 4
- In machine drawings dimensions should not be duplicated. Reference dimensions can be used
if necessary to duplicate. True or False? - There are no existing standards for creating technical drawings of mechanical parts and assem-
blies. True or False?
Answers
- Tolerance is the total amount a dimension may vary.
- Fillets are concave metal corner (inside) surfaces.
- True
- False. It depends on how the part will be used.
- It consists of a drawing that conveys the completed shape of the product as well as its overall
dimensions, and the various parts of the product assembled in their relative working positions. - They are (1) Unified or National Form Threads, which are called National Coarse, or NC, and
(2) National Fine, or NF threads. - The diameter of the pitch circle (or line), which equals the number of teeth on the gear divided
by the diametral pitch. - There are three classifications of helical springs: compression, extension, and torsion.
- True
- False
CHAPTER 8 (THE MEANING OF SYMBOLS)
Questions
- What is one of the main functions of graphic symbols on blueprint drawings?
- The American National Standards Institute (ANSI) specifies exactly how the “North Point”
should be represented on a drawing. True or False? - Why do electrical drawings typically include a symbol legend or list?
- Piping used in commercial and residential plumbing applications must not include plastic mate-
rial. True or False? - HVAC drawings show the location of the heating, cooling, and air-conditioning units as well as
piping and ducting diagrams. True or False? - How can one improve HVAC drafting productivity and efficiency.
- A symbol should be scaled to determine its size. True or False?
Answers
- It is to reference other drawings within the set.
- False
- Because electrical symbols are not standardized throughout the industry.
- False
- True
- Using custom HVAC CADD programs can increase drafting productivity and efficiency.
- False