GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

•Purpose is to describe the engineering intent of parts and assemblies

•Uses symbols to specify geometric characteristics and dimensional requirements

•Current GD&T standard: ANSI/ASME Y14.5M-2009

•Symbols for:

•Form and profile tolerances, orientation tolerances, location tolerances, runout tolerances

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

•Feature control frame

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

Examples of Modifiers

•MMC – Maximum Material Condition

•LMC – Least Material Condition

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

•ISO standard of preferred metric limits and fits: In the dimension 16h11, the tolerance zone is specified by a letter and a number, I.e. h11. An uppercase letter indicates that the tolerance applies to the hole; a lowercase letter indicates the tolerance applies to the shaft.

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GD&T

GD&T

GD&T•Basic Dimension: Theoretically exact, untoleranced dimensions that specify the perfect location, size, shape, or angle of a feature.

•Basic dimensions are identified by enclosing the dimension in a box.

•Basic dimensions specify theoretically exact value from which variations are defined through feature control frames as well as toleranced features and notes.

•General tolerances do not apply to basic dimensions.

GD&T

GD&T – Datum Surfaces and Features

GD&T – Datum Surfaces and Features

GEOMETRIC DIMENSIONING AND TOLERANCING (GD&T)

GD&T – Datum Surfaces and Features

GD&T – Datum Surfaces and Features

GD&T – Datum Surfaces and Features

GD&T – Datum Surfaces and Features

GD&T – Datum Surfaces and Features

GD&T – Datum Surfaces and Features

GD&T – Datum Surfaces and Features

GD&T – Datum Surfaces and Features

GD&T – Datum Surfaces and Features

GD&T – Datum Surfaces and Features

GD&T – Datum Surfaces and Features

GD&T – Datum Surfaces and Features