In butchery, the top blade steak comes from the chuck section of a steer or heifer. The steaks are cross-cut from the top blade subprimal, also known as Infraspinatus. They have a line of tough connective tissue down the middle, creating a tough steak best suited to braising. It is becoming more popular and profitable to abstain from cross cutting the top blade and instead produce flat iron steaks which eliminate the connective tissue.
Kosher butchers refer to this cut as "minute steak" - compare minute steak.