Sheet metal rolling, connector production

[Javert]

I need something like a connector, in reality it is a tube, which has a diameter of 3 mm in the narrow part, 4 mm in the wide part and a height of about 25 mm.
In reality, it is made of 0.5 mm brass sheet. . The connector has a seam, the picture is only indicative.
I need a relatively large number of connectors and I would like to be able to manufacture them. Does anyone have experience with this?
I have an idea how it was originally produced
1. A 26 x 9.4 mm rectangle was cut out of the brass sheet
2. In the place of expansion, pressing creates a 5 mm wide, 0.5 mm deep recess
If I don't see a problem here, what I don't know is how to make a tube from a semi-finished product prepared in this way?
They could make it in the 50s, so should I.
I need about a hundred of them.
I am willing to invest time and money in the production / acquisition of the product, but I need to know how to do it

 

[ELECTRONICIENSENIOR]

Hello,

You could contact this french connector maker :

Nos produits - MFOM

mfom.fr

 

[carpenter]

The principle of bending sheet metal into a tube
In the first step, you make a U profile by pressing it into a mold
second step, watch the video

 

[KlausST]

Hi,

does it need to be sheet made?
Why not buy a brass pipe with 3mm inner diameter and 4mm outer diameter (0.5mm thickness)

****
Your picture of post#1 shows different outer diameter, I guess this would be impossible to make froma sheet.

Klaus

You may pre-form them in a press. .. and finish them in the center of three spinning rolls
The roll diameter should not be bigger than 6 times the outer diameter of your brass device.
A (stainless) steel rod with diameter of 3mm (or a little less) could support the rolling process to get more precise results.

 

[Javert]

The original is made of sheet metal and it seems logical to me to do it the same way.
While maintaining the key parameters it could be different, but it has to have the expansion that it holds in other parts.
I thought of a tube with a wider wall or a brass log and a lathe, but it takes a lot of work.
bent from sheet metal seems to be the most viable way.
the question is whether it could be pressed, the form would have to take into account the elevation, something like

Ringing on three rolls is only used for larger diameters or material thicknesses that cannot be solved by pressing.
With a diameter of 3 mm, I can't imagine it somehow.