Final review Flashcards
dimension lines can be given from extension lines, dimension lines, leaders, figures, notes and symbols
true
what needs to be dimensioned
lengths, diameters/radius, angles and locations
should dimensions be duplicated?
never
how should a diameter/radius dimension look like?
extension line pointing towards the centre of the hole
can the arrows look different on the drawing?
NO
which dimension is in the correct imperial form: 0.214 or .214
.214
do you dimension hidden lines?
no only in the view(s) where it’s not a hidden dimension
what is the purpose of general notes?
simplify/complement dimensioning, indicate rounds/fillets, indicate sharp edges, dimensioning system (imperial or metric)
which is correct form? 24”, 2”-0, 2”-3
2”-0 and 2”-3 (values can’y exceed 12”
can you dimension in metric and in imperial at the same time?
yes write it like a fraction + metric over inch always
how to draw reference dimension
put value in brackets
how to identify a not-to-scale dimension
it will be underlined
if you have rounded ends do you need to identify the radius?
no just overall dimensions are necessary (length x width)
do plain round holes need notes next to dimension?
yes indicate manufacturing requirements
how to avoid drawing repeated features
use a phantom line + EQSP + #features
what angle to use if chamfer angle isn’t specified
45°
what is a full section view
cutting plane passes fully through the part
what is a half section view
two cutting planes perpendicular to each other where one-half of the view is in section and one quarter of full object is removed
what is an offset section
cutting plane can be bent to include several surfaces
what is a broken-out section view
specific section so not necessarily 1/2 or 1/4
what is an aligned revolved section view
what is a detailed removed section view
slope symbol
right angle triangle with ratio
what is chain dimensioning
dimensions are right next to each other in a line
what is datum dimensioning?
when one side of the dimension lines of all parts line up together (draw it then check google)
what is the actual size
measured size
what is basic size
theoretical size from which limits for the dimension are derived by application of allowance/tolereance
what is design size
refers to size from which limits of size are derived by application of tolerances
what are limits of size
min/max sizes permissible for a specific dimension
what is the nominal size
design size
what is tolerance
difference between max/min limits of size
what is bilateral tolerance?
tolerance permitted in both directions (x and y)
what is unilateral tolerance
tolerance only permitted in one direction
what is the maximum material size? (MMC)
maximum amount of material thus maximum limit of size for a shaft or an external feature or, minimum limit of size for a hole or internal feature
what is direct dimensioning?
where least tolerance is accumulated
what is a clearance fit
fit between mating parts having limits of size so prescribed that a clearance always results in assembly
what is an interference fit
fit between mating parts where part won’t fit into each other (negative overlap)
what is a transition fit
where fit between mating parts having limits of size so that either a clearance or interference will be present in assembly
