High Speed Steel Planer & Jointer Knives have new grade T-1 high-speed steel with 18% tungsten content. For comparison, this steel is much harder than M-2 HSS which typically has 12% tungsten. Crafted on state-of-the-art equipment, each knife is ground, honed and individually hand-hammered to exacting tolerances. Many standard sizes available individually or in sets. Packaging: Bulk in flat tubes.