# How to compute the weight of a titanium or stainless steel rod using UliEngineering in Python

In the following example, we’ll compute the weight of a pure (i.e. grade 2) titanium rod of dimensions `Ø10mm x 100mm`

and compare it to a 1.4404 steel rod of the same size.

In order to do that, we’ll use `UliEngineering.Physics.Density`

containing pre-defined density values and `UliEngineering.Math.Geometry.Cylinder`

to compute the volume of the rod.

In order to run this script, first install UliEngineering.

```
from UliEngineering.Math.Geometry.Cylinder import *
from UliEngineering.Physics.Density import *
weight_14404 = cylinder_weight_by_diameter(diameter=0.010, length=0.1, density=Densities['1.4404'])
weight_titanium = cylinder_weight_by_diameter(diameter=0.010, length=0.1, density=Densities['Titanium'])
print(f"Weight of 1.4404 rod: {weight_14404:.3n} kg")
print(f"Weight of Titanium rod: {weight_titanium:.3n} kg")
```

This prints:

```
Weight of 1.4404 rod: 0.0628 kg
Weight of Titanium rod: 0.0354 kg
```