Gotcha - it's interesting to know the weakest link here is the stem... Which personally, I have no problem with that. If I had to choose my weakest link - it'd be the stem
Were this particularly long stems? What region do you live in (hot/cold)? Where is the car stored (UV exposure)? Humidity? Which wheel was it on (front/rear - left/right)? Did that side of the car face south (again, UV exposure)? Frequent rotation? Any distinguishing characteristics on the failed stem (discoloration in rubber or steel, steel fracture, etc. - compare to other good stems)? Point of failure (stem base, stem valve, inner seal ridge, vertical or horizontal crack)?
Sorry for the question bombardment - this is failure analysis treb
