Geometric Tolerancing (GD&T) Basics

Overview

Engineering reference data for Geometric Tolerancing (GD&T) Basics in drawing tools.

Key Formulas

Scale Factor

$SF = \frac{\text{drawing size}}{\text{actual size}}$

Ratio of drawing to real dimensions.

Tolerance

$T = \text{max} - \text{min}$

Allowable variation in dimensions.

Aspect Ratio

$AR = \frac{w}{h}$

Width to height ratio.

Variables

References

• Original Source