I'm getting quite good at breaking sockets lately ---
I've posted my disappointment in these 1970s vintage SK sockets before. Seems the 1/4" and 3/8" drive sets were pretty suspect as far as quality and durability are concerned. Back in 1978 I purchased a complete set -- 1/4", 3/8" and 1/2" drive (metric and standard) from my local auto parts store. It was their premium line and they were discounted heavily because the store was switching over to Challenger as their premium offering.
I purchased the sets because SK had a great reputation; both my dad and grandpa swore by the brand. Needless to say, I've broken many sockets out of all those sets -- no impact use, just ratchets, breaker bars, and spinners. Today I was helping a friend install new motor mounts on his vehicle and used a breaker bar to loosen the lug nuts and the old motor mounts -- 19mm and 18mm respectively. Within an hour, I had two cracked sockets --
Stay away from 1970's vintage SK sockets guys --
Maybe I should send these to SK so that they can inspect these things for quality issues. I've never broken more sockets than from these SK sets.