[Drew Hause]

Decarbonized steel is not a pattern welded laminate, it is "Bessemer process homogenous wrought iron" and was sourced from Remington Arms.

Pages 503 & 504 of "The Parker Story" state that Parker changed the name to "Plain Steel" as Remington was using the name "Decarbonized" on their newly introduced Model 1873 & 1875/1876 Hammer Lifter doubles. 889 guns were made with Decarbonized Steel barrels.

From Fire-Arms Manufacture 1880 U.S. Department of Interior, Census Office "The earliest use of decarbonized steel or gun-barrels is generally credited to the Remingtons, who made steel barrels for North & Savage, of Middletown, Connecticut, and for the Ames Manufacturing company, of Chicopee, Massachusetts, as early as 1846. It is also stated that some time about 1848 Thomas Warner, a the Whitneyville works, incurred so much loss in the skelp-welding of iron barrels that he voluntarily substituted steel drilled barrels in his contract, making them of decarbonized steel, which was believed by him to be a novel expedient. The use of soft cast-steel was begun at Harper's Ferry about 1849. After 1873, all small-arms barrels turned out at the national armory at Springfield were made of decarbonized steel(a barrel of which will endure twice as heavy a charge as a wrought-iron barrel), Bessemer steel being used until 1878, and afterward Siemens-Martin steel."

The tensile strength is a bit more than pattern welded barrel steel, about the same as AISI 1018 Low Carbon (Mild) Steel, a bit less than Whitworth fluid steel, and considerable less than modern 4140 chrome moly steel.
The tensile strength could be increased by "cold rolling"; ie. Winchester Standard Ordnance “Rolled” Steel.