No power tools involved here. I was working on a power steering line bracket that was held in by two 10mm bolts. First one came out nice, but as soon as I tugged on the second one, the entire socket split in half. These are late 70's vintage sockets and they have been bothersome. For some reason I have had many failures with SK sockets from that era. Mostly common 1/2" drive sizes such as 19mm and 9/16, but also a few 1/4" drive sizes such as 12mm and 14mm.
I have never had as many sockets break in my entire life as the SK versions from those late 70's lots.
Time to get a new one -- will order another SK 10mm to keep the set intact.