Overview#
A bill of materials (BOM) lists the parts in an assembly with quantities and identifying data. In Fusion the BOM is generated from the component structure: each unique component (counting instances) becomes a line. Bodies do not appear. So a clean BOM starts with a clean component tree (see Components vs Bodies).
Fusion offers BOM output in two main places:
- The Bill of Materials in the Design workspace: a list of all items in a design, which you can customize, share by link and export (.csv among other formats). It is not available with a Fusion for personal use license or with single-user storage, and Electronics BOMs are not supported by it.
- A parts list on a drawing (Drawing workspace > Tables > Parts List), with balloons.
Third-party add-ins and PLM tools can export more formats (general information, not Autodesk documentation).
Where to find it#
| Task | Location |
|---|---|
| Set part number, description, material | Right-click component > Properties; or edit the cell in the BOM |
| Open the BOM | Design workspace > Assemble group > Bill of Materials (design must be saved at least once) |
| Refresh | BOM dialog > More > Refresh BOM if data looks out of date |
| Show/hide/reorder columns | Column Settings at the top right; drag headers |
| Layout | Layout Switcher top left: Structured or Parts Only |
| Which BOM | Switcher top right: Working, Pending, Released (the last two for Fusion Manage subscribers) |
| Drawing parts list | Drawing workspace > Tables > Parts List (or Tables > Table, Type Parts List), then pick the drawing view |
| Export | BOM dialog > Export BOM > choose a format such as .csv; a notification gives a Download file link |
Note: not confirmed in Autodesk's documentation: an "Exclude from BOM" or "Purchased" property. Earlier text claimed both.
Step by step#
Prepare the components#
- Give every component a meaningful name and, if you have a numbering scheme, a Part Number.
- Fill in Description and Material. Make sure you apply a material (not only an appearance) if you plan to report mass.
- Decide for each component whether it is a part, a purchased item, or a reference/helper. Keep helpers (layout sketches, envelope bodies, cutting tools) out of the component tree you want in the BOM, for example in a separate design (general guidance; no exclude option is documented).
- Check for instances: identical parts should be copies made with Paste, which stay linked, rather than Paste New, which creates an independent copy.
Generate the Design BOM#
- Save the design, then choose Assemble > Bill of Materials. Each save updates the BOM, and you can keep the dialog open while you work.
- Use Column Settings to choose the columns you want.
- Choose Structured (hierarchical) or Parts Only (parts and quantities, no hierarchy).
- Check that quantities match expectations.
- Click Export BOM and pick .csv; the whole BOM is exported regardless of selected rows.
You can edit a cell directly if the property is not locked or read-only; the change is saved to the cloud and mirrors the Properties dialog. You may override quantities (for example spare bolts) and, if your hub enables it, mass, volume, area and length, width and height; overrides appear in orange, must be greater than zero, and are reset if you save the design as latest.
Put a BOM on a drawing#
- Create a drawing from the assembly and add a base view of it.
- On the toolbar choose Tables > Parts List (or Tables > Table with Type Parts List) and click the drawing view.
- Choose the Structure: First Level (first-level components only) or All Levels, and click to place the table. Balloons are added automatically to label the view.
- Double-click the parts list to edit Structure, Table Direction (Up or Down) and unit display (for example Mass).
- A table can also be exported as CSV (Drawing: Export a table as CSV).
Options reference#
| Property/Option | What it does | Notes/default |
|---|---|---|
| Part Number | Identifier in the BOM. | Component property; editable in the BOM. |
| Description | Text description in BOM. | Free text. |
| Material | Material assigned. | Component property. |
| Quantity | Count of instances. | Calculated; can be overridden in the BOM. |
| Mass / volume / area / dimensions | Physical properties. | Can be overridden when enabled in your hub; derived totals (Total Mass, Density) cannot. |
| Layout | Structured or Parts Only. | Layout Switcher. |
| Compare to Model | Highlights rows that differ from the design (More > Compare to Model). | Working BOM, Structured layout only. |
| Export format | Choose from the Export BOM menu (such as .csv). |
Quantities and structure#
Instances vs copies#
- Paste copies stay linked to each other (changing one updates all): the BOM shows one row with quantity N.
- Paste New creates an independent copy. In a collaborative editing hub the pasted component gets a new, unique part number, so identical-looking copies can appear as separate rows.
Sub-assemblies#
In the Structured layout, assemblies and sub-assemblies appear hierarchically; Parts Only lists parts and quantities without hierarchy. For purchasing the Parts Only view is usually what you want; for manufacturing structure, Structured (general guidance).
External components#
Components inserted from other designs (external components) appear in the BOM. Recipients of a shared BOM link will not see referenced components they lack access to. After updating a referenced component use More > Refresh BOM. Keep part numbers unique across designs (general guidance).
Standard content#
Parts inserted from McMaster-Carr can carry catalog part numbers; check the Part Number column after insertion (see McMaster-Carr and Standard Content).
Making the BOM purchase-ready#
- Use a consistent naming scheme: "PN-0012 Bracket" or "Screw, SHCS M5x16".
- Put the supplier part number in the Part Number field for purchased parts, or in Description if the field is used internally.
- Keep helper components out of the BOM structure.
- Keep fasteners and filter the CSV afterward if you do not want to cost them.
- Export CSV and clean up in a spreadsheet: sort, add costs, supplier.
- Re-export whenever the design changes; the file is a snapshot.
Tips and pitfalls#
Tip: Treat the BOM as a test of your model: odd quantities and generic names reveal structure problems.
Tip: If you need revision, lifecycle or cost columns, see the Working/Pending/Released BOMs and estimated-cost overrides available with Fusion Manage, or a separate PLM/BOM tool, rather than hand-editing exports.
Warning: Bodies are not listed. If you modeled a bolt as a body inside the housing component, the BOM will not show it.
Warning: An exported file is a snapshot. Re-export after changes.
Warning: Renaming a component changes all instances and changes how the BOM row reads. If a name is changed after a drawing was issued, check the drawing's balloons and table.
Tip: After design changes, check that the drawing parts list matches the BOM (general guidance).
Tip: Use Properties > Physical properties to check mass per component and compare to expectations (weight budget).
Availability and BOM versions#
The Bill of Materials is available only in the Design workspace and is not available with a Fusion for personal use license or single-user storage. Fusion for education shows a slightly different dialog. To see BOMs for older versions of a design, open that version and open the Bill of Materials. You can also share a link to the BOM with hub members who have at least Viewer access to the design (Copy Link at the top right).
Worked example: an 11-row BOM that should be 4#
A designer inserts one M5 x 16 socket head screw from the catalog, copies and pastes it seven times, and then copies a washer eight times with Paste New. Illustratively, the BOM could show:
| Item | Name | Qty |
|---|---|---|
| 1 | Base | 1 |
| 2 | Bracket | 1 |
| 3 | Screw M5x16 | 8 |
| 4-11 | Washer M5 (8 unique definitions) | 1 each |
That is 11 rows when the purchasing list should be 4. The washers are separate component definitions because Paste New creates independent copies. Fix: delete seven of the washers, copy the remaining one with Copy and Paste from the Browser context menu so the copies stay linked, and re-place them with joints. The BOM collapses to Base 1, Bracket 1, Screw 8, Washer 8. A quick way to spot this problem is to sort the BOM by name: runs of identical names with quantity 1 mean unique copies.
Mass roll-up example#
Material and mass are only reliable if every component has a material. With a 6061 aluminum base of 0.42 kg, a steel bracket of 0.18 kg and 8 steel screws at 0.004 kg each, the total is 0.42 + 0.18 + 8 x 0.004 = 0.632 kg. If one component keeps the default material, the total is off by the density ratio for that part alone (general figures: steel about 7.85 g/cm3 against aluminum about 2.7 g/cm3, nearly 3 to 1), so a surprising total usually points to a missing material rather than a wrong model.
Failure modes and fixes#
| Symptom | Cause | Fix |
|---|---|---|
| A purchased bolt does not appear | It is a body inside a component | Convert to its own component. |
| Duplicate rows for identical parts | Paste New created independent copies | Replace with Paste copies. |
| A row is missing | The design was not saved, the BOM is stale, or the component is not accessible to you | Save, then More > Refresh BOM; check access to referenced components. |
| Drawing parts list disagrees with the Design BOM | Structure setting differs (First Level vs All Levels) or the drawing is out of date | Match the Structure setting and update the drawing. |
| Sub-assembly children missing | Layout or parts list set to First Level | Use Parts Only or Structured layout, or All Levels on the drawing. |
| CSV opens with everything in one column | Wrong delimiter in your spreadsheet locale | Import with the correct delimiter rather than double-clicking. |
Release checklist#
- Every component has a unique part number and a description.
- Every component has a material (or is flagged as purchased).
- Helper components are kept out of the BOM structure.
- Quantities were spot-checked against the model: count the visible bolts and compare.
- The BOM was exported or the drawing updated after the final design change, and the file version is noted in your document control record.
Practice exercise#
- Open an assembly with at least a base, a bracket, and 4 bolts (insert bolts via Insert > McMaster-Carr or copy/paste one bolt 4 times).
- Set Part Numbers and Descriptions for the base and bracket.
- Generate the BOM. Confirm bolts are one row with quantity 4.
- Move a helper component ("Layout envelope") out of the assembly structure and re-check the BOM.
- Export to CSV; open it in a spreadsheet and confirm the columns.
- Create a drawing with the BOM table and balloons.
Expected result: a CSV and a drawing table listing each unique part once with the right quantity, and no helper components.
Stretch challenge#
Build a small assembly of a base, a lid, 4 screws and 4 washers, with the screws inserted as external components and the washers as local copies. Give the base part number PN-1001 and the lid PN-1002, then intentionally break the BOM: paste the washers with Paste New and leave one component without a material. Export the BOM, find both problems from the data alone (eleven rows instead of four, and a missing material cell), fix them in the model, and re-export. Expected result: four rows (Base 1, Lid 1, Screw 4, Washer 4, with no helper components) and a total mass within 1% of your hand calculation.
Related#
- Components vs Bodies
- McMaster-Carr and Standard Content
- External References
- Large Assemblies