On March 12, 1906 Blaw Collapsible Steel Centering Company was formed in New Jersey to manufacture and market re-usable steel forms for molding concrete in heavy construction. The initial product line of the Blaw company was based on the patented invention of Jacob B. Blaw of Philadelphia. This invention was for a better way to set the concrete for the sewers than by means of the wooden forms normally used for such work.
In 1909 Luther Knox and Irvin F. Lehman became associated in the establishment of the Knox Pressed and Welded Steel Co. Luther Knox pioneered the use of pressed and welded steel, in place of previously used non-ferrous castings, for the manufacture of water-cooled equipment for open hearth furnaces and for other high temperature applications.
The Blaw-Knox Company name was adopted July 6, 1917, marking the merger of Blaw Steel Construction Company with the Knox Pressed and Welded Steel Company. This merger introduced the company to the steel industry and also brought together the three Lehman brothers into one business firm.
In 1927 the company added radio towers to its products.
During its growth years Blaw-Knox acquired a number of companies. In 1929 A.W. French & Company became part of Blaw-Knox. This was a factor in eventually establishing a complete package of road-building equipment. Blaw-Knox is now a brand name of this equipment and is now part of Ingersoll-Rand.
Blaw-Knox experienced less growth during the years of the Great Depression, but stayed in the black. The company was also involved in the manufacture of many products to support the efforts in WWII, such as: cast armor for naval vessels, turrets for tanks, anti-aircraft Bofors* gun mounts, Naval gun slides and mounts, rockets, projectiles, torpedo launching equipment and the operation of a 16-inch shell line, to name only a few. For it’s excellence in the war effort, Blaw-Knox won seven Army-Navy “E” awards with 16 stars.
The company served four basic market categories: (1) the metallurgical industries; (2) chemical process and nuclear industries; (3) public service industries; and (4) public works and highway construction industries. —
*Bofors is a Swedish company.
One more note of interest is that Blaw-Knox built one of its early manufacturing facilities in Hoboken, PA. The town was renamed Blawnox, PA and is located next to Pittsburgh. (I was born in Hoboken, NJ)

The above information was obtained from a 28 page booklet, published in 1957 entitled: “Blaw-Knox Growth Through Invention And Enterprise,” which is the text of an address, given by W. Cordes Snyder, Jr., who was president of the Blaw-Knox company of Pittsburgh, PA. at the time.

In early 1933, WLW began construction of a new 500,000 watt superpower facility at Mason, Ohio after approval of the Federal Radio Commission. RCA supplied the 500KW transmitter. A new 831 foot, half wave, end-fed, Blaw-Knox double diamond-shaped vertical antenna weighing 136 tons was erected for the small sum (in today’s dollars) of $46,000. The wider, middle of the tower structure is 35 ft. square. A concrete lined pond was built in front of the transmitter building for transmitter cooling. Water was pumped through specially designed water cooled tubes, and was then sprayed into the air by fountains, returning back into the pond.