Here evidence the company (of no relation) was in business at least back to 1939:
"The training of chain makers was no routine process; specialqualifications were required, but in spite of the careful screeningof applicants, only 2 out of every 10 likely prospects successfullycompleted the training program. Then, too, training was relativelyslow since the apprentice had to work up through the various sizesof chain. In spite of these handicaps, which caused a slight delayin meeting early schedules, the chain industry by 1941 had builtup its capacity and was fulfilling all production requirements. Inthe revival of the industry, the :McKay Co. of Pittsburgh playeda leading role. This company had no heavy chain capacity in 1939,but within 2 years it had built the largest wrought iron chain makingplant in the world at ~fcKees Rocks, Pa .. and was producing more heavy chain than all other American manufacturers combined."
Source: (page 184) http://www.ibiblio.org/hyperwar/NHC/NewPDFs/USN/USN Admin Histories/USN.Bureau.Ordnance.WWII.pdf
Other references show the company was still in business in the 1950s.
Don.....