Fig Symmetrical Outlines

1.8.9 Round Holds. Round holes are dimensioned as shown in Fig. 1-34. Where it is not clear that a hole goes through, the abbreviation THRU follows a dimension. The depth dimension of a blind hole is the depth of the full diameter from the outer surface of the part. Where the depth dimension is not clear, as from a curved surface, the depth should be dimensioned. For methods of specifying blind holes, see Fig. 1-34.

1.8.10 Slotted Holes. Slotted holes are dimensioned as shown in Fig. 1-35. The end radii are indicated but not dimensioned.

1.8.11 Counterbored Holes. Counterbored holes may be specified as shown in Fig. 1-36. Where the thickness of the remaining material has significance. this thickness (rather than the depth) is dimensioned. For holes having more than one counterbore, sec Fig. 1-37.

1.8.12 Countersunk and Counterdrilled

Holes. For countersunk holes, the diameter and included angle of the countersink are specified. For counterdrilled holes, the diameter and depth of the counterdrill are specified. Specifying the included angle of the counterdrill is optional. See Fig. 1-38. The depth dimension is the depth of the full diameter of the counterdrill from the outer surface of the part.

1.8.12.1 Chamfered and Countersunk Holes on Curved Surfaces. Where a hole is chamfered or countersunk on a curved surface, the diameter specified on the drawing applies at the minor diameter of the chamfer or countersink. See Fig. 1-39.

1.8.13 Spotfaces. The diameter of the spotfaced area is specified. Either the depth or the remaining thickness of material may be specified. See Fig. 1-40. A spotface may be specified by note only and need not be delineated on the drawing. If no depth or remaining thickness of material is specified, the spotface is the minimum depth necessary to clean up the surface to the specified diameter.

1.8.14 Machining Centers. Where machining centers are to remain on the finished part, they are indicated by a note or dimensioned on the drawing. See ANSI B94.11M.

1.8.15 Chamfers. Chamfers are dimensioned by a linear dimension and an angle, or by two linear dimensions. See Figs. 1-41 through 1-44. Where an angle and a linear dimension are specified, the linear dimension is the distance from the indicated surface of the part to the start of the chamfer. See Fig. 1-41.

1.8.15.1 Chamfers Specified by Note. A

note may be used to specify 45° chamfers, as in Fig. 1-42. This method is used only with 45° chamfers, as the linear value applies in either direction.

1.8.15.2 Round Holes. Where the edge of a round hole is chamfered, the practice of para. 1.8.15.1 is followed, except where the chamfer diameter requires dimensional control. See Fig. 1 -43. This type of control may also be applied to the chamfer diameter on a shaft.

1.8.15.3 Intersecting Surfaces. Where chamfers are required for surfaces intersecting al other than right angles, the methods shown in Fig. 1-44 are used.

1.8.16 Keyseats. Keyseats are dimensioned by width, depth, location, and if required, length. The depth is dimensioned from the opposite side of the shaft or hole. See Fig. 1-45.

1.8.17 Knurling. Knurling is specified in terms of type, pitch, and diameter before and after knurling. Where control is not required, the diameter after knurling is omitted. WTiere only a portion of a feature requires knurling, axial dimensioning is provided. See Fig. 1-46.

1.8.17.1 Knurilng for Press Fit. Where required to provide a press fit between parts, knurling is specified by a note that includes the type of knurl required, its pitch, the toleranced diameter of the feature before knurling, and the minimum acceptable diameter after knurling. See Fig. 1-47.

Press Fit TolerancingPress Fit Tolerancing

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