Werkzeugstahl Wärmebehandlung

Heat treatment temperatures for common tool steels

Tool steels achieve their final properties through controlled heat treatment. Hardening and tempering temperatures vary significantly between grades. This reference covers the critical temperatures for the most commonly used tool steels in machining and toolmaking.

• A2 (Air-Hardening): Austenitise 925-980 deg C, air quench (or pressurised gas). Temper 175-540 deg C depending on target hardness. Distortion is minimal because it cools in air. Good toughness. Used for dies, punches, and gauges.
• D2 (High-Carbon High-Chromium): Austenitise 995-1025 deg C, air/oil quench. Temper 150-540 deg C. High wear resistance (12% Cr, 1.5% C). Used for cold-work dies, shear blades, forming rolls.
• H13 (Hot-Work): Austenitise 995-1040 deg C, air/oil quench. Temper 540-650 deg C (always temper above secondary hardening peak at 500 deg C to avoid brittleness). Used for die casting dies, extrusion tooling, forging dies.
• O1 (Oil-Hardening): Austenitise 790-815 deg C, oil quench. Temper 175-260 deg C. Simple heat treatment; can be done in most shops. Good for gauges, tooling, and fixtures.
• M2 (High-Speed Steel): Austenitise 1190-1230 deg C (requires high-temperature furnace), oil/air/salt quench. Triple temper at 540-595 deg C (secondary hardening). Cutting tools maintain hardness to 550 deg C.

How to use this Tool Steel Heat Treatment Reference Guide

Identify your tool steel grade. Look up the austenitising (hardening) temperature and quenching medium. Temper at the temperature corresponding to your target hardness. For critical tooling, use a professional heat treater with vacuum furnace capability -- the consistency and quality assurance are worth the cost.