Asme Y14.5m-1994: Dimensioning And Tolerancing

Imaginary, mathematically perfect points, axes, or planes used as reference points for measurements.

A rectangular box that serves as the primary "sentence" for GD&T. It contains the geometric symbol, the tolerance value, material modifiers (like MMC or LMC ), and datum references.

Controls the physical placement of features relative to each other or a datum. Profile of a Surface, Profile of a Line Controls the boundary of a feature's outline. Runout Circular Runout, Total Runout Controls variation in a surface when rotated about an axis. Building Blocks of the Language Dimensioning and Tolerancing ASME Y14.5M-1994

Drawings should define the final part geometry without dictating the specific manufacturing processes (e.g., drilling vs. punching) used to achieve it. Standard Reference Temperature: All dimensions apply at 68∘F68 raised to the composed with power cap F ( 20∘C20 raised to the composed with power cap C ) unless noted otherwise.

Unless otherwise specified, the limits of size of an individual feature of size control both the size and the form (shape) of that feature. Controls the physical placement of features relative to

Controls the shape of a feature regardless of its location or orientation. Parallelism, Perpendicularity, Angularity Controls the rotation of a feature relative to a datum. Location Position, Concentricity, Symmetry

The standard relies on several fundamental rules that guide how dimensions and tolerances are applied: Building Blocks of the Language Drawings should define

Dimensions and tolerances typically apply when the part is in its "free state" and not being forced or bolted down. Key Components of GD&T in Y14.5M-1994