O1 is an oil-hardening tool steel which may be hardened from fairly low temperatures with little size change. This grade combines deep-hardening qualities with a fine-grained structure, affording good initial production runs, and continued production after grinding.
Typical applications include: Blanking Dies, Engraving Tools, Forming Tools, Gauges, Jewelers Hobs, Paper Knives, Taps (hand), Trim Dies
Typical chemistry: Carbon .90% * Manganese 1.25% * Silicon .30% * Chromium .50% * Tungsten .50%