Uncomfortable_close_01

Yes, I knew this would be fun to solve, and it was! Thanks for a puzzle most people would never understand.

They were the models before the Nexus series.

What is a SQT?
The machine is a Mazak Quick Turn Nexus 200-II MY, also known as a QT-200.

Is that a Mazak SQT?

Very interesting, thanks for the really cool photo.

No, it was stainless steel and the marking became history when I was done.

Good photo, sharp and clear. A lot of people won't have any idea what they're looking at or what your explanation means!

By the way, if that piece is titanium, writing 91,38 on it in marker pen may lead to eventual failure of the part at that location. But it'll be OK if the 91,38 is machined off during the manufacturing process.

I don't usually do puzzles of this type but this one is intriguing. I'll save it and solve later.