Part modelling with 46 sketch constraints and 23 features, each one key away.
The Part workbench is where parametric CAD for mechanical engineers starts: sketches that solve predictably, features with full history and a surfacing set for the shapes a prismatic modeller cannot reach. It ships in every seat, Standard at $2,490 and Professional at $3,890.
Part / limits
- Sketch constraints
- 46
- Feature types
- 23
- Entities per sketch
- 5,000
- Features per part
- 4,000
- Surface continuity
- G0 / G1 / G2
01Sketch solver
A sketch solver that tells you which constraint is wrong.
Numeric Newton-Raphson with a graph decomposition pass first, so small clusters solve independently.
Before any numbers move, the solver splits the sketch into rigid clusters and solves each one alone. A 400-entity sketch of a gasket usually breaks into dozens of tiny independent problems, and each converges in two or three iterations. That is why dragging a point in a large sketch feels immediate: only the cluster you touched is solved again.
Over-constrained sketches are the daily pain in every modeller. Ours does not just turn red. It finds the minimal conflicting set, usually two or three constraints, highlights them, and offers to suppress the most recent one. Under-defined geometry shows in blue with the remaining degrees of freedom counted in the status bar, so "2 DOF left" tells you exactly how far a sketch is from fully defined.
Hard limits are 5,000 entities per sketch and 12,000 constraints. We have seen customers hit the first with imported DXF floor plans. Past that size, sketching is the wrong tool; import as a reference curve and build features from it.
02Constraints46 types
All 46 sketch constraints, grouped by what they hold.
Solver / constraint set
| Group | Count | Constraints |
|---|---|---|
| Geometric | 20 | Coincident, horizontal, vertical, parallel, perpendicular, tangent, concentric, coradial, collinear, equal length, equal radius, midpoint, symmetric, fix, pierce, point on curve, smooth G2, merge, horizontal point alignment, vertical point alignment |
| Dimensional | 12 | Linear distance, horizontal distance, vertical distance, radius, diameter, angle, arc length, chord length, ellipse major axis, ellipse minor axis, perimeter, offset distance |
| Curve | 8 | Spline end tangency, spline end curvature, spline control point fix, spline handle length, conic rho, ellipse axis angle, slot width, polygon side count |
| Reference | 6 | On plane, projected edge, intersection curve, silhouette edge, equal curve length, pattern driven |
Dimensions accept expressions and named variables: wall = 2.5mm, then 2*wall + 0.1 anywhere a number goes. Variables are shared across a part and can be pushed from an assembly.
03Features23 types / remappable
Twenty-three features, each with a default shortcut.
Single letters for the features you use fifty times a day. Shift for the subtractive or variant form. Alt for the rarer ones. Every binding can be remapped in Options and exported as a .swskeys file so a team shares one layout.
The shortcut sheet as a printable PDF sits on the docs page.
- ExtrudeBlind, through-all, up-to-face, mid-plane, with draft and thin-wall options.E
- Cut extrudeSame end conditions, removes material. Flip side with one click.Shift+E
- RevolveFull or partial, about a sketch line, edge or axis.R
- Cut revolveGrooves, undercuts, O-ring glands.Shift+R
- SweepProfile along a path with guide curves and twist control.W
- LoftBetween 2 and 32 profiles, with tangency at either end.L
- BoundarySolid or surface from curves in two directions, G2 capable.B
- FilletConstant radius, edge chains, face fillets, curvature-continuous option.F
- Variable filletRadius set per vertex or at parameter points along the edge.Shift+F
- ChamferDistance-distance, distance-angle, vertex chamfer.C
- ShellUniform or multi-thickness, inward or outward.S
- DraftNeutral plane, parting line and step draft for cast and moulded parts.D
- RibFrom an open sketch, both sides or one, with draft.Shift+B
- HoleISO and ANSI clearance, tapped, counterbore, countersink, pipe thread tables.H
- ThreadCosmetic for drawings or modelled helical geometry for print and CAM.T
- Linear patternOne or two directions, skip instances, vary by table.P
- Circular patternAbout an axis, equal or explicit spacing.Shift+P
- Curve patternInstances along a sketch or edge chain, normal or fixed orientation.Alt+P
- MirrorFeatures, faces or bodies across a plane.M
- CombineAdd, subtract, intersect between bodies in a multi-body part.K
- SplitCut a body by a plane, surface or sketch into separate bodies.Shift+K
- Fill surfacePatch an n-sided boundary with contact, tangent or curvature conditions.Alt+F
- ThickenTurn a surface or quilt into a solid of set thickness.Alt+T
04Surfacing
Surfacing for handles, housings and the odd blend that will not fillet.
This is engineering surfacing, not Class-A styling. It exists so a mechanical engineer can close a grip, blend a casting transition or patch an imported model without leaving the part. If your job is automotive exterior panels, buy Alias; we will not pretend otherwise.
Every surface feature lives in the same history tree as the solids, so a lofted handle updates when the housing it sits on changes width. Knit and Thicken turn a closed quilt back into a solid that the simulation and CAM workbenches can use without a conversion step.
Surface tools / 9
| Tool | Continuity | Typical use |
|---|---|---|
| Extruded / revolved surface | G0 | Split tools, parting surfaces |
| Swept surface | G1 | Lips, seals, cable channels |
| Lofted surface | G2 | Grips, ducts, transitions |
| Boundary surface | G2 | Four-sided patches between edges |
| Fill surface | G2 | N-sided holes, three-way corners |
| Offset surface | G1 | Wall thickness checks, tool faces |
| Trim / untrim | — | Cleaning imported quilts |
| Knit | — | Gap closing to 1e-4 mm, then solid |
| Zebra and curvature analysis | — | Checking G1 against G2 on screen |
05Seat
Part comes with every seat. So does a real trial.
No edition gates the Part workbench. A Standard seat at $2,490 carries every feature and every constraint on this page. Professional at $3,890 adds simulation and five-axis posts, not modelling tools. Accredited students get the same Part workbench at $0.
Migrating from SolidWorks or Inventor? The constraint names map almost one-to-one, and our support team will rebuild one of your typical parts on a screen share during the trial so you can compare tree to tree. What we will not do is promise your old feature history converts. It does not, from any vendor, and the parts you import arrive as exact solids you build on.
Day 0
Request the trial. Download link and key within one business day.
Week 1
Model three of your own parts. Ask support for the remapped shortcut file if you come from another package.
Day 30
Keep the files either way. Buy against a written quote, or keep reading them in
sws-view.
Other workbenches
- 02
Assembly
Mates, large-assembly mode, the 50,000-part benchmark.
- 03
Drawing
GD&T drawing software to ISO 128 and ASME Y14.5.
- 04
Simulation
CAD with built-in FEA, NAFEMS-checked.
- 05
Sheet metal
K-factor tables for 5052, 1008 and 304.
- 06
CAM-Post
Posts for Fanuc, Haas, Heidenhain, Siemens 840D.