Has anyone experienced bad fluorescent tube batches? Today I got a haul from my school of fluorescent tubes, and in there was a few NOS Tungsram early 2000s made F40T12 CW tubes. It seemed odd that they are putting unused tubes in the 'bad' tube pile. I brought home 4 of them and they seemed unused. I cleaned them, tested them and safely put them away, and as I was walking from the shelf a few hours ago after sorting everything I hear a crack and a hiss. I check witch one committed suicide, and I see that all four tubes had they necks broken off.  What the hell is happening??? I am so confused. Only the CW ones did that. Probably in the factory there were some defect in the glass stress annealing part of the manufacturing, because it can't be that it was just a coincidence of some sorts.  All four tubes lost vacuum, because ends cracked off cleanly. It's such a shame, because tungsram CW T12s are very good tubes, with very good quality CRI and overall product.  I now think that they put these tubes in the 'bad' tube pile because the whole batch of these tubes kept failing on them and they just put the remaining tubes in the bad pile, and as I brought them home and cleaned them and tested them the fragile glass somehow developed a weak point and cracked. I am so, so mad right now... Such a nice tubes went to waste...

Yup.  I run across a runt in a case of tubes every once in awhile- dead on arrival.  Vacuum loss.  No signs of cracks.  I see many weak filliments/cathodes from Phillips since they went to the Gen-2 of their Altos back in 2004-2008 and since then.  You put some in the fixtures out of the box and can see a cathode or filament (or whatever you call them now a days) on the bottom of the tube.  Most of the time you are good right out of the box but it seems once they have been powered up for a little while, they become VERY brittle and if you take the tubes out to change to another fixture or to clean or whatever, they don't like to be jarred very much or again you'll find yourself with a broken cathode and EoL soon after.    The first gen of Green capped alto T8s were awesome!  Life wise and would take a beating.  Thicker glass.  Even the 2nd gen onward of the T12s are like that with the weak cathodes    

With GE- Since about 2007ish- I've run into having to return several cases of T8 tubes because up to 5 or more tubes in a large case will remain super dim after startup-  I'm not talking the initial start up dimness of a brand new tube that goes away after 5 minutes, but rather staying dim.  Not enough mercury perhaps.  I believe this issue has lessened in the past year or so.  I also saw this issue at several of the public schools that I helped retrofit over to LED- there were relatively new GE tubes in fixtures with good ballasts (verified because I brought some of the tubes and ballasts home and bench tested them) where the tubes were super dim.  Not pink mercury starved dim but very dim. 

With Sylvania- it's just the occasional 1 dead lamp in a case that I see. 

I am so, so mad right now... Such a nice tubes went to waste...

It's not worth getting mad over.  Trust me.  They are only light bulbs/tubes   Many more out there.