Really? Never come across that before!
I needed a blade cut for our old Rover 75, our local cobbler cum key cutter refused cos I couldn't tell him the maker of the blank, ( it came with the car) next I tried Timpsons, they refused unless I bought the blade off them.
This is a bit surprising but one has to assume that at least have some idea of what they are doing. Never had the problem but then I don't get keys cut very often and. as you say, always let them supply the blank! Wonder what their cutting tools use that cannot cut the metal of the blanks!
The key cutter told me that there had been a number of blanks bought from eBay that had shattered during the cutting process and most key cutters are wary of people who supply their own blanks. Probably poor quality brass or summat. To be honest my local key cutter is rubbish anyway, none of the keys I've had from him work without me doing a bit of filing.
