For a different perspective, "History of New York Shipyards mentions them:
The first manufacturer of edge tools in New York City, with ship carpenters' tools as a specialty, was John Conger. He opened a small blacksmith shop in 1814 in Suffolk street, but in 1818 he branched out in making edge tools while located in Grand street.' This was the period when prosperity was abroad in the country. He continued in the business at different places until 1845, when he closed up while located at 33 Attorney street. He was the pioneer edge tool manufacturer of New York City, i
William Horton, who had served his apprenticeship with John Conger, opened a shop in Fifth street near Lewis in 1837, and removed to Lewis street near Fifth street in 1840; was succeeded by Horton & Arnold in 1853, who remained on the old site until 1868: Samuel B. Arnold had been an employee of William Horton.
About 1841 Lewis Watts and James M. Sheffield, who had also been in the employ of William Horton, started in the same line of business in Avenue D, and these two manufacturers had the monopoly of their line of business- in New York City until about 1852, when W. S. Hawkins, who had a large blacksmith shop in Third street, near the shipyards, commenced the manufacture of edge tools in the same locality as the other manufacturers.
This was during the period when all trades allied to shipbuilding were driven to the top notch. These manufacturers all went out of business after the close of the War of the Rebellion, on account of the shipyards being unemployed, f
