Bills of materials from Inventor to Excel: always in your own template

Your assembly is finished. The parts list is correct. And then the work begins that nobody puts on their resume: getting the bill of materials out of Inventor and into Excel, in the form that purchasing, production, or your ERP system expects. Selecting, copying, pasting, shifting columns, dropping in a logo, fixing that one typo in the material. Every order again.

Exporting a bill of materials (BOM) to Excel in Inventor should be a matter of seconds, not a quarter-hour chore where mistakes creep in. In this article you will read why the manual route is so error-prone, and how you solve it with an export to a fixed Excel file, built from columns you set up yourself and fed by iProperties that are correct.

Why manual BOM export leads to errors

The parts list in an Inventor drawing is fine for showing on a sheet. But the moment that list has to leave the drawing and go to Excel, the shifting begins. And with every manual step you lose control.

A few recognizable situations:

• Copying and pasting shifts columns. You paste the parts list into an empty tab, but the order of the drawing does not match the order purchasing wants. So you start cutting and pasting columns. One wrong row and the quantities suddenly belong to the wrong item.
• Everyone makes their own version. One engineer puts "Material" in column C, another in column E. Work preparation receives three different layouts and has to read all three in differently. Your template exists on paper, but not in practice.
• The BOM and the iProperties drift apart. Someone corrects a part number or material directly in Excel, not in the model. The next time you export, that correction is gone and the old value is back. What is even correct anymore?
• Manual retyping. As soon as you type values over instead of exporting, it is only a matter of time before an 8 is mistaken for a 0 or a position number is skipped.

The painful part is this: the error often only shows up further down the line. With purchasing ordering the wrong profile. With the cutter set to a length that is no longer correct. Or with the cost estimate counting on a quantity of 4 while there are 6. The bill of materials is the document that half the factory relies on, and that is exactly where you allow manual work.

The solution: bill of materials (BOM) to Excel in Inventor in a fixed format

The core of the problem is that you are doing two things at once: pulling data and creating formatting. Split those and it becomes calm. The data comes from the model, the formatting is fixed in settings that you set up correctly once. That is exactly what Export BOM from Thundercad does.

Export BOM pulls the bill of materials from your active assembly and writes it to Excel in a fixed format: with thumbnails, your company logo, and the iProperties you have chosen as columns. Not today's layout, but the layout that is always the same. Purchasing, production, and your ERP receive exactly the same structure every time.

What that means in practice:

• You decide the columns. In the settings you add iProperties as columns, and you put them in the order you want. After that, the export is identical for everyone.
• No more cutting and pasting. The data lands in the right place, in the right order. You do not shift any columns, because there is nothing to shift.
• The values come from the model. Material, quantity, description, part number: what is in the iProperties is in the export. No manual intermediate step where it can go off the rails.
• You switch thumbnails and logo on or off. An image per item and your company logo at the top: on or off, your choice. Set up once, always the same result.

iProperties that are correct: the foundation under a reliable BOM

An export is never better than the data underneath it. Export messy iProperties neatly to Excel and you have neat mess. So the gain is not only in the export, but also in keeping the metadata in your model in order.

This is where the iProperty Menu comes into play. Instead of Inventor's standard iProperties dialog, with tabs full of fields you do not use 90% of, you work with one configurable data card per document type. You decide which fields are visible, in which order, and with which dropdowns. An engineer sees exactly the fields that matter, and picks material from a list instead of typing it in every time.

That has a direct effect on your bill of materials:

• Fixed choices instead of free text. A dropdown for material prevents "S235", "S 235", and "st37" from all appearing in the same BOM as if they were different things.
• No more empty fields. If the important fields are up front and clear, they get filled in too. Empty descriptions and missing part numbers show up immediately in the BOM.
• One source of truth. The iProperty in the model is leading. The BOM in Excel is a derivative. If you correct something, you do it in the model, and the next export is automatically correct.

The iProperty Menu works per document type, so you set up the data card for your parts, your assemblies, and your drawings separately. This ensures that exactly the fields your Export BOM needs, such as description, material, part number, and supplier, are consistently filled in everywhere. If you enter the project or order number neatly via that data card, it also comes along neatly in every column of your bill of materials.

Do the math: what does manual work cost per BOM?

Just a calculation example: note, these are assumptions, not measured values. Suppose that per assembly you spend ten minutes neatly transferring the parts list to your Excel file: pasting, arranging columns, adding the logo, checking. That sounds harmless.

Now suppose your team delivers five assemblies a day this way. Then you spend 50 minutes a day retyping and shifting: work that is not engineering, but administration. Over a work week that is more than four hours. And those four hours do not even include the time to fix errors that only surface later at purchasing or production.

The real costs, by the way, are not in the minutes, but in the errors. One wrongly ordered profile, one missed position on a large order, and you have lost a whole month's time savings to fixing and explaining. An export that always comes from the same source and always lands in the same format removes those errors at the root.

How to set it up

The setup is a one-time job and after that you are done with it. In broad strokes:

1. Determine your iProperty fields. Set up per document type in the iProperty Menu which fields you need for the bill of materials: think description, material, part number, supplier. Use dropdowns where the values are fixed.
2. Fill in your models neatly. Make sure those fields are filled in consistently via the data card, so that no gaps appear in your bill of materials.
3. Set up your columns. In the Export BOM settings you choose which iProperties go along as columns and in which order they appear. There you also switch thumbnails and your company logo on or off.
4. Export. Open your assembly, click Export BOM, and your bill of materials is in Excel: with your columns in the right order, thumbnails and logo, ready for purchasing or your ERP.

Working with an ERP system and prefer not to work via a separate Excel file? Then Thundercad can be linked to your ERP via the Dashboard, so that BOM data lands there directly. That link is set up to measure, handy if you want to not only export the bill of materials, but also push it through automatically.

More than just the bill of materials

Export BOM does not stand alone. It is part of Thundercad, the toolbox that automates the repetitive work in Inventor. Once you have the bill of materials neatly out of the model, you want the rest of the production package correct in one go too.

With Batch Publish you set out all production documents in one step: PDF, DWG, DXF, and STEP, also in combination with Vault. One click instead of twelve steps: think of 48 PDFs in about 6 seconds instead of publishing file by file. This way the bill of materials does not come loose from the model, but in the same pass as all your drawings and exports. That keeps the complete documentation package consistent with the assembly it comes from.

Does it fit your situation?

Export BOM is part of Thundercad, the toolbox for Autodesk Inventor from Cadkunde. It works on Windows 10 or 11 with Autodesk Inventor 2025 or newer and an active Autodesk account. Companies such as Little Giant Europe, Van Egten, Banzo, and Mannen van Staal already work with it.

It can be used per user: EUR 30 per user per month, or EUR 300 per user per year, which is two months free. Prices are excluding VAT. You can try it 30 days free, without a credit card, so you simply test on your own assemblies whether the export matches the columns your purchasing and ERP expect.

Want to know more about the individual tools? Take a look in the knowledge base or on the homepage.

Frequently asked questions

How do I determine which columns end up in my bill of materials?

In the Export BOM settings you set up the columns yourself: you add iProperties as a column and put them in the order you want. There you also switch thumbnails and your company logo on or off. The right data then lands automatically in the right column, the same every time.

How do I prevent the BOM and the model from drifting apart?

Keep the iProperties leading and always correct in the model, not in the exported Excel. With the iProperty Menu you manage that metadata efficiently via one configurable data card per document type. The export is then always a reliable derivative of the model.

Does the BOM export also work together with Vault or an ERP system?

Export BOM delivers your bill of materials in Excel. If you want to push the data through to your ERP automatically, then Thundercad can be linked to your ERP system via the Dashboard. That link is set up to measure; contact Cadkunde for this.