Standard Geometric Dimensioning & Tolerancing Reference Guide for Automotive & Aerospace Parts
| Symbol | Characteristic | Tolerance Type | Recommended Inspection Method |
|---|---|---|---|
| ⏥ | Flatness | Form | Optical 3D Scanning / Laser Tracker / Surface Plate |
| ⏤ | Straightness | Form | Optical Comparator / Portable CMM Arm |
| ⚪ | Circularity (Roundness) | Form | VMM (Vision Measuring Machine) / Rotary Table CMM |
| ⌭ | Cylindricity | Form | High-Accuracy CMM / Structured Light Scanning |
| ∥ | Parallelism | Orientation | Datum Alignment via CMM / Blue Light Scanner |
| ⊥ | Perpendicularity | Orientation | Precision Square / Coordinate Measuring Machine |
| ∠ | Angularity | Orientation | 3D Point Cloud to CAD Deviation Analysis |
| ◎ | Concentricity | Location | Multi-Axis CMM Inspection |
| ⊕ | Position (True Position) | Location | CMM Datum Reference Frame (DRF) Verification |
| Surface Profile | Profile | Full-Field 3D Scanning Color Map Comparison |