Introduced in 1977 with a maximum sulfur level of .010%, Fineline� steels successfully addressed the market concern about lamellar tearing of conventional plate steels when used in highly restrained welded joints.

For certain applications, where even more stringent mechanical properties and internal cleanliness were required, the next generation of Fineline was developed in 1985 with a maximum sulfur level of .005%. Military alloy plate steels took advantage of Fineline’s more uniform tri-axial mechanical properties, while the tooling industry benefited from the improved cleanliness.

In 1990, to satisfy the requirements for HIC (hydrogen induced cracking) testing of plate steels used in the construction of process vessels,  A516 steel with a maximum heat analysis of .002% sulfur was offered. For this grade and application, the maximum sulfur level for Fineline was further reduced to .001% in 1992.

Although sulfur levels of .001% and .002% have been marketed primarily in A516 plates, Bethlehem also produces other specifications to very low sulfur levels.

The Fineline process can be applied to any plate steel melted in Bethlehem Lukens Plate's Coatesville, Pennsylvania electric furnace steelmaking complex where heats of 165 tons are produced. The equipment at this facility makes possible the rapid and efficient production of steels to precisely-controlled chemistries essential to the Fineline process.

Fineline plate steels are available from Bethlehem as flat plate or cut to desired shape as a flamecut product. They can also be used as backing steel for Bethlehem's roll-bonded clad plate steels.