# Datum reference frame & GD&T

**Part:** BRK-2040-AL  
**DRF:** A | B | C

| Datum | Feature | Role |
|---|---|---|
| A | Outer face of long leg (rack face) | Primary planar |
| B | Outer face of short leg | Secondary planar, ⊥ A |
| C | Edge at inside corner | Tertiary stop |

## Feature control frames

| Feature | Control | Tolerance | Datum |
|---|---|---|---|
| Face A flatness | ⎓ | 0.05 mm | — |
| Face B ⊥ A | ⊥ | 0.10 mm | A |
| M4 hole pattern position | ⊕ | Ø0.20 mm MMC | A\|B\|C |
| M5 hole position | ⊕ | Ø0.20 mm MMC | A\|B\|C |
| Thickness 3.00 | size | ±0.10 mm | — |

Inspector works from this DRF; callouts are production intent, not decoration.