Unit 15 Geometric Dimensioning and Tolerancing 275 Copyright Goodheart-Willcox Co., Inc. any measuring location along the part. Tolerance mea- surements are taken with a dial indicator by rotating the part 360° around a datum axis. The full indicator movement (FIM) of the dial indicator must be less than or equal to the specified tolerance. See Figure 15‑32. When applied to surfaces established around a datum axis, circular runout controls cumulative form and location characteristics. When applied to surfaces existing at right angles to a datum axis, circular runout controls wobble. Total Runout A total runout tolerance is a type of runout tolerance that provides composite control of all surface elements of a feature relative to a datum axis. When applied to a cylindrical feature, a total runout tolerance establishes a tolerance zone defined by two cylinders that are separated by a distance equal to the tolerance. When applied to a planar feature, a total runout tolerance establishes a tolerance zone defined by two parallel planes that are separated by a distance equal to the tolerance. A total runout tolerance is applied simultaneously to all measuring locations along the part. Tolerance measurements are taken with a dial indicator by rotat- ing the part 360° around a datum axis. The full indica- tor movement of the dial indicator must be less than or equal to the specified tolerance across the entire sur- face. See Figure 15‑33. the feature control frame. The points define the extent of control and are identified with labels on the drawing. Profile of a Surface A profile of a surface tolerance is a three-dimensional geometric tolerance used to control variation of all points making up an entire surface. The tolerance zone extends across the true profile of the feature, as shown in Figure 15‑31. All points along the surface must lie within the tolerance zone. Profile of a surface is also referred to as surface profile. Runout Tolerances Runout is a condition that describes the variation of a surface relative to a datum axis. Runout tolerances are applied to surfaces established around a datum axis and surfaces existing at right angles to a datum axis. Runout tolerances are always applicable RFS. A runout tolerance specification must have at least one datum feature reference. There are two types of runout toler- ances: circular runout and total runout. Circular Runout A circular runout tolerance is a type of runout tol- erance that provides control of circular elements of a surface relative to a datum axis. A circular runout tolerance establishes a tolerance zone defined by two circles that are separated by a distance equal to the tolerance. The tolerance is applied independently at Drawing Interpretation .004 tolerance zone Goodheart-Willcox Publisher Figure 15-31. Profile of a surface.