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Home › Steel › To Case-Harden Polished Iron
To Case-Harden Polished Iron
The iron, previously polished and finished, is to be heated to a bright red and rubbed or sprinkled over with prussiate of potash. As is that boiling water is only 212 Fahr., and soon as the prussiate appears to be decompos- the gun was heated to 450° to give it its ed and dissipated, plunge the article into cold proper temper. water. When the process of case-hardening 3305. Grease for Anointing Gunhas been well conducted, the surface of the Barrels on the Sea-Shore. It is said that metal proves sufficiently hard to resist a file. an ointment made of corrosive sublimate and The last two plans are a great improvement lard will prove an effectual protection against upon the common method. By the applica- the rusting of gun-barrels on the sea-shore. ZINC--TIN.