YAOTENG Steel are stockholders and suppliers of L6 tool steel round bar and flat sections which can be sawn cut to your required sizes. L6 ground steel bar can be supplied, providing a high quality tool steel precision ground tool steel bar to your required tolerances. H13 tool steel is also available produced as Ground Flat Stock / Gauge Plate, in standard and non standard sizes.
Contact our experienced sales team who will assist you with your H13 tool steel enquiry.

L6 Tool Steel is a versatile, oil-hardening tool steel that is characterized by very good toughness. L6 tool steel is suitable for use as tools, dies, and machine parts, which require a good combination of hardness and toughness. The relatively high nickel content results in an alloy with greater impact toughness compared to the other common oil-hardening grades.

Preheat slowly to 750°C then increase the temperature more rapidly to 1050-1100 °C. Do not forge below 850°C. It is essential to cool the H13 slowly after forging, either in a furnace or in vermiculite.

Annealing must be performed after hot working and before re-hardening.

Heat at a rate not exceeding 400°F per hour (222°C per hour) to 1400°F (760°C), and hold at temperature for 1 hour per inch (25.4mm) of maximum thickness; 2 hours minimum. Then cool slowly with the furnace at a rate not exceeding 50°F per hour (28°C per hour) to 1000°F (538°C). Continue cooling to ambient temperature in the furnace or in air. The resultant hardness should be a maximum of 235 HBW.

For improved machinability, hold at 1400°F (760°C) for1 hour per inch (25.4mm) of maximum thickness; 2 hours minimum. Then cool slowly with the furnace cool from 1400°F (760°C) to 1250°F (677°C), hold for 8 hours, then air cool to ambient temperature. The resultant hardness should be a maximum of 192 HBW.

To minimize internal stresses in cross sections greater than 6 inches (152.4 mm) and to improve stability in tools that will be EDM'd after heat treatment, a soaking time of 8 to 10 hours at the tempering temperature is strongly recommended

Critical Temperature: Ac1: 1325°F (719°C)

Preheating: Heat at a rate not exceeding 400°F per hour (222°C per hour) to 1150-1250°F (621-677°C) and equalize.

Austenitizing (High Heat): Heat slowly from the preheat.
Furnace or Salt: 1450-1500°F (788-816C)
Soak for 30 minutes for the first inch (25.4 mm) of thickness, plus 15 minutes for each additional inch (25.4 mm).

Some prefer to do cryogenic treatment as an extension of the quench from the austenitizing treatment. Others prefer to cryogenically treat after tempering.

Temper immediately after quenching. Hold at temperature for 1 hour per inch (25.4 mm) of thickness, 4 hours minimum, then air cool to ambient temperature.

In general, we do not advise the welding of tool steel but users sometimes prefer to weld in order to avoid the cost of retooling. It should be remembered that this grade is an air hardening steel and that in welding the area of the weld attains a temperature of about 1000°C. Cracking is likely to occur during cooling unless proper precautions are taken. Popular methods of welding are atomic hydrogen and argon arc. We recommend you contact your welding consumables supplier who should provide you full assistance and information on welding tool steels.

Welding Procedure

We recommend you contact your welding consumables supplier who should provide you with full assistance and information on welding alloy steel grades.

Heat treatment temperatures, including rate of heating, cooling and soaking times will vary due to factors such as the shape and size of each L6 tool steel component. Other considerations during the heat treatment process include the type of furnace, quenching medium and work piece transfer facilities. Please consult your heat treatment provider for full guidance on heat treatment of tool steels.

Select the correct grade of wheel in consultation with the grinding wheel manufacturer. Ensure the grinding wheel is in good condition by means of a suitable dressing tool. Wet grinding is a preferable option using a copious supply of coolant. If dry grinding is resorted to then use a very soft wheel.

L6 tool steel is supplied in accordance with our ISO 9001 : 2008 registration.