Check the listing for details. 2/5" Heavy Duty Cold Chisel 6.5" Alloy Steel Octagonal Flat Cold Chisel. Condition: New. Listed at 15.67 USD. 1. Made from alloy steel (60Si2Mn), our chisel set is heat-treated and drop-forged for durability and toughness. This high-grade alloy steel ensures robust performance and resistance to corrosion. The baked enamel finish provides a protective layer that guards against rust, corrosion, and wear, ensuring long-lasting reliability for professionals and DIY enthusiasts.2. With an edge hardness of 55-58 HRC, our chisels are optimized for superior cutting abilities on hard materials such as wood, stone, and metal. The hardened blade enhances toughness and durability for demanding tasks, while the one-piece cold-forging technology provides strong load-bearing capacity and stable power transmission, making it easier to penetrate hard stone.3.