Armstrong was a relatively late entry as a maker of sockets and drive tools, as these tools were not offered until sometime after 1928. This was around the same time that J.H. Williams was first producing socket tools as well, and interestingly enough, the socket tools from Armstrong and Williams bear a striking resemblance. Not only are the styles, designs, and tool selection nearly the same, but all of the model numbers (even for socket sets) match as well. (Currently it's not known which company was actually first to market.)