Component weight from an uploaded STEP model
The weight of one component in a STEP, STP, IGES or IGS assembly is the volume of that component times the material density. Upload the .STEP, .STP, .IGS or .IGES file on this page. .IGS and .IGES are the same format. The file stays in the browser. Hide every other part. The weight shown is only the parts still visible. Show a part to put it back, or use Show all for the whole model. A SolidWorks .SLDPRT or .prt is converted to STEP in this tab and then weighed the same way. A .3ds mesh and a Rhino .3dm that already has a display mesh are weighed from that mesh. A .3ds file stores no unit, so its sizes are treated as millimetres. Type the material (steel, nylon, Delrin, PP, or any name on the list) or enter a custom density. Turn on Measure to check a length, diameter, radius or angle. Download saves a PNG of the view, and Download on the summary saves the numbers.
Weight from a STEP, STP, IGES or IGS model
A STEP model weight calculator does not read a mass property out of the CAD file. Most STEP exports store B-rep geometry, not a density. IGES and IGS use this same page. This calculator — for STEP, STP, IGES and IGS — reads the solid, measures volume, then applies the same workshop densities as plate and bar: mild steel 7.85 g/cm³, stainless 8.00, aluminium 2.70, and the rest of the catalogue. Hide a part to leave it out of the weight. Show it to put it back. The number is only the parts still on screen.
Formula
W = V_mesh × ρ
V from a closed triangle mesh · ρ in g/cm³
STEP model weight = CAD volume × density
STP, IGES and IGS use the same mesh as STEP
Example — closed steel cube 100 mm
V = 0.100³ = 0.001 m³
W = 0.001 × 7850 = 7.85 kg
A real STEP of a filleted block will sit a little under that if the mesh undersamples the fillets.
STEP mass, STP volume and 3D CAD weight
After the model loads, pick an alloy to calculate weight from a STEP file — or calculate mass from a STEP file, which is the same number. Volume is shown next to mass, so the page also works as a STEP volume calculator, STP volume calculator and CAD volume calculator. For 3D CAD weight (a CAD model or 3D model weight calculator) the export must be a closed solid; open surfaces and construction geometry do not enclose a volume.
Densities on this page
- Mild Steel · 7.85 g/cm³
- Carbon Steel · 7.85 g/cm³
- Stainless Steel 304 · 8 g/cm³
- Stainless Steel 316 · 8 g/cm³
- EN8 · 7.85 g/cm³
- EN19 · 7.85 g/cm³
- EN24 · 7.85 g/cm³
- D2 · 7.7 g/cm³
- H13 · 7.8 g/cm³
- Aluminium · 2.7 g/cm³
- Aluminium 6061 · 2.7 g/cm³
- Aluminium 7075 · 2.81 g/cm³
- Copper · 8.96 g/cm³
- Brass · 8.5 g/cm³
- Bronze · 8.8 g/cm³
- Titanium · 4.51 g/cm³
- Cast Iron · 7.2 g/cm³
- Nylon · 1.14 g/cm³
- Nylon 6 · 1.13 g/cm³
- Nylon 66 · 1.15 g/cm³
- Nylon 6 30% GF · 1.36 g/cm³
- Nylon 66 30% GF · 1.4 g/cm³
- Nylon 66 40% GF · 1.48 g/cm³
- Nylon 66 60% GF · 1.7 g/cm³
- PA46 · 1.4 g/cm³
- Delrin / Acetal · 1.41 g/cm³
- POM / Acetal · 1.4 g/cm³
- POM GF30 · 1.6 g/cm³
- ABS · 1.05 g/cm³
- ABS 30% GF · 1.3 g/cm³
- PVC · 1.4 g/cm³
- PP · 0.9 g/cm³
- PP Filled · 1.16 g/cm³
- HDPE · 0.95 g/cm³
- PMMA (Acrylic) · 1.17 g/cm³
- Polycarbonate · 1.2 g/cm³
- PC+ABS · 1.15 g/cm³
- PC-PBT · 1.35 g/cm³
- PC-PBT 30% GF · 1.5 g/cm³
- TPE · 1 g/cm³
- TPU · 1.28 g/cm³
How a toolroom uses STEP weight
Quotes often arrive as a STEP, not a cutting list. We open the solid, confirm it is the part we think it is, pick the alloy, and use the mass for a material take-off and a freight band. Use Measure if a hole, span or angle on the model does not match the email. Then we still weigh the stock on the shop floor before a certified shipping note.
Need to calculate weight from dimensions instead? Use the metal weight calculator. For a larger canvas to view the model and check dimensions — no mass — open the CAD Viewer. That page also opens a SolidWorks part, a 3D Studio mesh, and a Rhino file that already has a display mesh. It does not write a converted file. This weight page weighs those same files: STEP, STP, IGES and IGS, plus a SolidWorks .SLDPRT or .prt, a .3ds mesh, and a Rhino .3dm that already has a display mesh.