Symbols
Tolerances: Type of Tolerances; 1) Unilateral 2) Bi- Lateral type
Type of tolerance | Geometric characteristics | Symbol | Can be applied to a feature? | Can be applied to a feature of size? | Can affect virtual condition? | Datum reference used? | Can use
|
Can use
|
Can be affected by a bonus tolerance? | Can be affected by a shift tolerance? |
---|---|---|---|---|---|---|---|---|---|---|
Form | Straightness |
|
Yes | Yes | Yes |
No | Yes |
No |
Yes |
No |
Form | Planarity |
|
Yes | No | No | No | No | No |
No | No |
Form | Circularity |
|
Yes | No | No | No | No | No |
No | No |
Form | Cylindricity |
|
Yes | No | No | No | No | No |
No | No |
Profile | Profile of a line |
|
Yes | No | No | Yes |
No | No |
No | Yes |
Profile | Profile of a surface |
|
Yes | No | No | Yes |
No | No |
No | Yes |
Orientation | Perpendicularity |
|
Yes | Yes | Yes |
Yes | Yes |
No |
Yes |
Yes |
Orientation | Angularity |
|
Yes | Yes | Yes |
Yes | Yes |
No |
Yes |
Yes |
Orientation | Parallelism |
|
Yes | Yes | Yes |
Yes | Yes |
No |
Yes |
Yes |
Location | Symmetry |
|
? |
? |
? |
? |
? |
? |
? |
? |
Location | Positional Tolerance |
|
No | Yes | Yes | Yes | Yes | Yes | Yes |
Yes |
Location | Concentricity |
|
No | Yes | Yes | Yes | No | No |
No | No |
Runout | Circular runout |
|
Yes | Yes | Yes |
Yes | No | No |
No | No |
Runout | Total runout |
|
Yes | Yes | Yes |
Yes | No | No |
No | No |
Notes:
- When applied to a feature-of-size.
- Can also be used as a form control without a datum reference.
- When a datum feature-of-size is referenced with the MMC modifier.
- When an MMC modifier is used.
- Automatic per rule #3.
- The symmetry symbol's characteristics were not included in the version of the chart that this chart is derived from. The symmetry symbol was dropped from the Y14.5M standard around 1988 and re-added around 1994.
Symbol | Modifier |
---|---|
|
Free state |
|
Least material condition (LMC) |
|
Maximum material condition (MMC) |
|
Projected tolerance zone |
|
Regardless of feature size (RFS) |
|
Tangent plane |
|
Unilateral |
Notes:
- The symbol is not part of the 1994 version. See para. A5, bullet 3. Also para. D3. Also, Figure 3-8.
- The symbol appears in the 2009 version of the standard, and refers to unequal profile distribution.
- All the symbols above are used in a feature control frame to specify a feature's description, tolerance, modifier and datum references.
Read more about this topic: Geometric Dimensioning And Tolerancing
Famous quotes containing the word symbols:
“Children became an obsessive theme in Victorian culture at the same time that they were being exploited as never before. As the horrors of life multiplied for some children, the image of childhood was increasingly exalted. Children became the last symbols of purity in a world which was seen as increasingly ugly.”
—C. John Sommerville (20th century)
“As usual I finish the day before the sea, sumptuous this evening beneath the moon, which writes Arab symbols with phosphorescent streaks on the slow swells. There is no end to the sky and the waters. How well they accompany sadness!”
—Albert Camus (19131960)
“That way of inspiration
is always open,
and open to everyone;
it acts as go-between, interpreter,
it explains symbols of the past
in to-days imagery.”
—Hilda Doolittle (18861961)