Uom conversion confusion

Hi every body
I have a scenario
I buy raw material in “Lengths”
1 Length = 3660 mm
The material is stocked in Raw Material Warehouse with units of Length
I send this material to be cut to various sizes as per quantity defined in BOM
For Example
1 Length gives me a Quantity of 100 Numbers (36.6mm of 100 Numbers)
Now when i send the material to Subcontract for cutting
I raise a PO for 50 Numbers
I do a Stock Entry
In stock entry >> Qty Column>>it shows 0.5 Units
whereas i want it to be shown as 1830 mm
The use case is
The Subcontract accepts the material in mm only. Then only will he be able to arrive at the number of quantity that can be cut out of that 1830mm
Imagine if the Subcontract receives the Delivery in the form of 0.5 Length (it can lead to a confusion since he might not know the actual Length is of 3660 mm )
How to sort this out
With Regards

The default UOM should be mm. Then define a second UOM of Length with a conversion factor of 36. Something like this

When you raise yor PO, it should look like this:

After receipt , stock ledger like so:

Hope this helps.