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BOMproof

Free tool

A BOM from a STEP file, straight into Excel.

Choose your STEP file and download the BOM as Excel or CSV: per part with the total quantity, material and dimensions, and per assembly with the quantities per level. Free and without upload.

  • Your file stays on your computer
  • Free, no account needed
  • Up to 150 MB, AP214 and AP242

Want to check your drawing and BOM too? Compare with the full BOMproof

01 How it works

Three steps, no installation.

  1. Step 1

    Choose your STEP file

    Drag a .stp or .step file into the box, or pick it on your computer. Up to 150 MB.

  2. Step 2

    Your browser reads the model

    Product structure, parts, materials and dimensions are read in your own browser. Nothing is uploaded.

  3. Step 3

    View, check, download

    Rotate the 3D model, see where duplicate or loose parts are and download the BOM as Excel or CSV.

02 Free or full

The viewer looks at the model. BOMproof looks at everything.

This free tool reads your STEP file. In BOMproof your drawings and BOM are added, and every check becomes a report that you work through.

What you can do Free tool BOMproof
View, rotate and search the 3D model
Product structure and BOM to Excel
Check for duplicate and loose parts and materials
Compare the BOM from Excel and from the drawing with the model –
Check title block, revisions and materials on the drawing –
Notes as balloons on the drawing, also as PDF –
Tick off notes and keep report versions –
Projects with multiple assemblies –
File size up to 150 MB up to 500 MB
Where your file is stored only on your computer storage in the EU
Price free free pilot

03 Explanation

What you need to know.

Flat or structured

A STEP file contains the full product structure of the design. From it this tool makes two BOMs in one Excel file:

  • BOM (flat): every unique part once, with the total quantity in the whole design, the material and the dimensions (L × W × H in mm, large to small). Handy for purchasing and production planning.
  • Structure (structured): the design per level, with a position number (1, 1.1, 1.1.2), the quantity per parent assembly and the total. This is the build-up as in the tree of your CAD package.

Prefer CSV? It uses a semicolon as separator and a comma as decimal mark, so Excel with Dutch settings opens it correctly straight away.

How the quantities come about

The quantity is the number of instances of the part in the model, across all subassemblies: four legs in a frame that is in the machine twice count as eight. If a part is accidentally placed twice in exactly the same spot, it counts twice as well. The Check tab in the tool points out those cases, so you can correct them before the list goes to purchasing.

What is not in a STEP file

Parts without a 3D shape (glue, paint, cable by length) and properties such as supplier, price or part number from your PDM are usually not in a STEP export. The BOM from the model is therefore a good check, but not always the complete purchasing list.

Checking BOM and model against each other

Do you already have a BOM in Excel or on the drawing? BOMproof compares it line by line with the model: quantities, parts that are missing and parts that only exist in the model, with every deviation pointed out in 3D and on the drawing.

04 Frequently asked questions

Good to know.

01 How do I get a BOM from a STEP file?

Open the STEP file in the tool on this page and click "Excel" or "CSV". The BOM is taken from the product structure in the file: each part with the number of times it occurs in the design.

02 What is in the Excel file?

Three sheets. BOM: per part the total quantity, the material and the dimensions (L × W × H in mm). Structure: the design per level with position number, quantity per parent assembly and total. Info: file, CAD system and dimensions of the model.

03 Do the quantities match my CAD BOM?

The quantities are the number of instances in the model. If a part is accidentally placed twice in the same spot, it counts twice; the check in the same tool points those cases out. Parts that are only on the CAD BOM (without a 3D shape, such as paint or glue) are not in a STEP file.

04 Are part numbers and descriptions included?

Only what the CAD package writes into the STEP: usually the part name or file number, and with some packages the material. Properties such as supplier or price are not included in a STEP export.

05 Is my STEP file uploaded?

No. The file is read and processed in your own browser; nothing is sent to a server. Only the 3D model is stored locally in your browser, so the same file opens faster next time. If you consent to statistics, we anonymously count how often the tool is used and how large the models are; never file names or contents.

06 How large can the file be?

Up to 150 MB. Opening an 84 MB design for the first time took about half a minute on a laptop with 8 cores; after that the same file opens instantly from your browser. The larger the model, the more memory your computer needs.

Check model, drawing and BOM in one go.

The free tool looks at the 3D model. BOMproof puts your STEP model, PDF drawings and Excel BOM side by side and points out every deviation, in 3D and on the drawing. Book a demo with your own design.