Bosch are probably made in China these days and they have at least a 20% fail rate right out of the tube. The older ones were/are made in India and prior to that France. Chinese made nozzles are poor. Any person can buy them off Alibaba.com for around .52 cents a pop. I tried a lot of 100 a few years ago. Over a year of tinkering with them and all but a few out of that 100 failed entirely. Anyone who thinks it’s just a matter of just calling the parts store to exercise some sort of 24-month warranty has a lot of extra time on their hands. Right now Monark was /is the only German maker of nozzles. They took out DES circa 2014 from memory. You can still find DES branded nozzles floating around. Most of the German lathes have been shipped off to Eastern Europe or beyond. Italy’s Bosio are headed the same way. Closing in on my 1,000th set of injectors here shortly and I’ve concluded the global powers will choke these old oil burners out of existence in the years to come by getting rid of simple items like nozzles. I tried unsuccessful for over a solid year to find any USA manufacturer to make me some nozzles. I provided the specs and drawings. Even offered $100 a piece and not one USA firm could lift a finger. I tried India mart and going through Alibaba.com and tons of interest but zero follow through

German made or Italian made is the last refuge of some notion of quality.