The answer to your question is - sort of…!
Facom’s “standard” screwdriver back then was the “Enduro”. They look similar to yours but have all black handles (with red highlights) and are a hard material.
The Enduro tips only came in standard sizes - for example an 8mm tip was 0.7mm thick. These standard metric sizes fit o.k. in Imperial screw slots, but of course you are best to use metric drivers with metric screws, and vice versa.
The Drivers you have are ‘Ergotwist”. They are very similar, but use the soft red material in the handle.
The main difference, was that the Ergotwist were made in a far greater range of sizes. For example, an Ergotwist 8mm driver could have a standard tip of 0.7mm, or a thicker one of 1mm, depending on what you ordered.
That may be what you are encountering.
Sadly, the Ergotwist are one of the few Facom design’s that didn’t stand the test of time. I think it was their first attempt at a soft material, and a lot of them are starting to disintegrate. The Enduro, the orange acetate handles, and the wooden handles, all last just fine. As I suspect do the current patterns.
