TYPE OF 
TOLERANCE

CHARACTERISTIC
AND SYMBOL

DATUM
REFERENCE

IMPLIED
CONDITION

ALLOWABLE
MATERIAL MODIFIERS

TOLERANCE
ZONE SHAPE

KEY POINTS TO REMEMBER

LOCATION

POSITION

YES

RFS

MMC OR LMC
ON THE TOLERANCE IF THE TOLERANCE IS APPLIED TO A FEATURE OF SIZE OR ON A DATUM REFERANCE IF THE DATUM IS A FEATURE OF SIZE.


CYLINDRICAL

TOTAL WIDTH

WITH THE MMC MODIFIER

  1. PERMITS FUNCTIONAL GAGING TECHNIQUES
  2. ALLOWS ADDITIONAL TOLERANCE BASED ON SIZE (BONUS)
  3. RELATIVELY INEXPENSIVE

POSITION:
Describes the perfect (theoretically exact) location of individual features in relationship with other feature(s) or a datum reference.

POSITION TOLERANCE ZONE:
Defined as a zone which the center, axis, or center plane of a feature of size is permitted to vary from its true (theoretically exact) position.

OR

(where specified on an MMC or LMC basis) a boundary, defined as the vertual condition, located at the true (theoretically exact) position, that may not be violated by the surface or surfaces of the considered feature.

Note: There are numerous applications for position control. The following is only one example as it applies to holes. Consult with the standard regarding other applications for position control.