Din 509e06x02 Exclusive 99%

It is a 0.6 mm wide, 0.2 mm deep flat-bottomed undercut with rounded edges, used primarily to clear the run-out of threads on a precision shaft.

The standard code structure typically looks like this: DIN 509... [Coating] [Thickness] [Color/Type] din 509e06x02 exclusive

If you are writing a specification or manufacturing to this old code: It is a 0