LINEAR
TOLERANCES
GUIDELINE (IMPERIAL)
DIMENSION |
NORMAL* |
PREMIUMS** |
UP
TO 1/2" |
±.
005 |
±.
003 |
UP
TO 1" |
±.
005 |
±.
004 |
UP
TO 2" |
±.
010 |
±.
005 |
UP
TO 3" |
±.
015 |
±.
008 |
UP
TO 4" |
±.
015 |
±.
010 |
UP
TO 5" |
±.
020 |
±.
010 |
UP
TO 6" |
±.
020 |
±.
010 |
UP
TO 7" |
±.
030 |
±.
015 |
UP
TO 8" |
±.
040 |
±.
015 |
UP
TO 9" |
±.
040 |
±.
015 |
UP
TO 10" |
±.
050 |
±.
020 |
LINEAR
TOLERANCES GUIDELINE
(METRIC)
DIMENSION |
NORMAL* |
PREMIUMS** |
UP
TO 15 mm |
±0.13 |
±0.08 |
UP
TO 30 mm |
±0.13 |
±0.10 |
UP
TO 55 mm |
±0.25 |
±0.13 |
UP
TO 80 mm |
±0.38 |
±0.20 |
UP
TO 105 mm |
±0.38 |
±0.25 |
UP
TO 130 mm |
±0.51 |
±0.25 |
UP
TO 155 mm |
±0.51 |
±0.25 |
UP
TO 180 mm |
±0.76 |
±0.38 |
UP
TO 205 mm |
±1.02 |
±0.38 |
UP
TO 230 mm |
±1.02 |
±0.38 |
UP
TO 255 mm |
±1.27 |
±0.51 |
* Normal tolerances are those can
be controlled in casting.
** Premium
tolerances require secondary controls
and processes to comply with print
specifications.
ANGULARITY
Angular tolerance on
investment castings should not be less
than ±1/2 ° .
CONCENTRICITY AND ROUNDNESS
Out of round is the radial difference between
a true circle and the cast surface diameter. The following table is a guide for
out of round tolerance:
(IMPERIAL)
HOLE DIAMETER |
DEVIATION FROM TRUE |
UP
TO 1/2" |
±. 003 |
UP
TO 1" |
±. 005 |
UP
TO 1 1/2" |
±. 008 |
UP
TO 2" |
±. 010 |
(METRIC)
HOLE DIAMETER |
DEVIATION FROM TRUE |
UP TO 15 mm |
±0.08 |
UP TO 30 mm |
±0.13 |
UP TO 40 mm |
±0.20 |
UP TO 55 mm |
±0.25 |
Concentricity tolerance varies according to straightness
at about ±. 005" (±
0.13 mm) per linear inch of difference between points of measure.
PARALLELISM AND PERPENDICULARITY
Tolerances less than .010" (0.25 mm) T.I.R. may require secondary machining.
FLATNESS AND STRAIGHTNESS
Flatness, a rough tolerance guide would be .003" (0.08 mm) T.I.R.,
(Total Indicator Reading), for each 1/4" (6.35 mm) thick section. This
variation will be apparent in surfaces of 1" (25.4 mm) or more linear
dimension.
Straightness, a constant section will be axial bow of approximately
.005" (0.18 mm) per linear inch under normal tolerance and about .003" (0.08 mm) per inch under premium tolerance.
|
