Specialized skill for geometric dimensioning and tolerancing specification per ASME Y14.5 and ISO 1101
The GD&T and Drawing Creation skill provides specialized capabilities for geometric dimensioning and tolerancing specification per ASME Y14.5 and ISO 1101, enabling proper documentation of design intent for manufacturing.
Primary Datum (A)
Secondary Datum (B)
Tertiary Datum (C)
| Function | Recommended Datum Features |
|---|---|
| Mounting surface | Primary: Mounting face |
| Shaft alignment | Primary: Axis (A-B pattern) |
| Hole pattern | Secondary/Tertiary: Pattern center |
| Symmetric part | Primary: Plane of symmetry |
| Symbol | Control | Datum Required |
|---|---|---|
| Straightness | Line element deviation | No |
| Flatness | Surface deviation | No |
| Circularity | Cross-section deviation | No |
| Cylindricity | Combined circularity + straightness | No |
| Symbol | Control | Datum Required |
|---|---|---|
| Perpendicularity | 90 degrees to datum | Yes |
| Parallelism | Parallel to datum | Yes |
| Angularity | Specified angle to datum | Yes |
| Symbol | Control | Datum Required |
|---|---|---|
| Position | True position from datums | Yes |
| Concentricity | Axis coincidence | Yes |
| Symmetry | Median plane coincidence | Yes |
| Symbol | Control | Datum Required |
|---|---|---|
| Circular runout | Single revolution check | Yes (axis) |
| Total runout | Full surface check | Yes (axis) |
| Symbol | Control | Datum Required |
|---|---|---|
| Profile of a line | 2D outline control | Optional |
| Profile of a surface | 3D surface control | Optional |
Position tolerance = 2 * sqrt((dx)^2 + (dy)^2)
Where:
dx = deviation in X from true position
dy = deviation in Y from true position
| Modifier | Effect | Application |
|---|---|---|
| MMC (M) | Bonus tolerance as size departs | Assembly clearance |
| LMC (L) | Bonus at LMC | Wall thickness control |
| RFS | No bonus | Default per Y14.5-2018 |
Cylindrical: Position of holes (diameter symbol)
Rectangular: Position of slots
Spherical: Ball location (S diameter symbol)
Standard Views
Section Views
Detail Views
Dimension Placement
Notes
{
"part_model": "CAD file reference",
"functional_requirements": {
"assembly_interfaces": "array",
"critical_features": "array",
"fit_requirements": "clearance|transition|interference"
},
"manufacturing_method": "machined|cast|molded|sheet_metal",
"inspection_method": "CMM|optical|manual",
"standard": "ASME_Y14.5|ISO_1101"
}
{
"drawing_info": {
"drawing_number": "string",
"revision": "string",
"sheet_count": "number"
},
"datum_reference_frame": {
"primary": "string",
"secondary": "string",
"tertiary": "string"
},
"geometric_tolerances": [
{
"feature": "string",
"tolerance_type": "string",
"value": "number (mm)",
"datums": "string",
"modifiers": "string"
}
],
"critical_dimensions": "array",
"bom": "array of components"
}