A Buyer's Guide to P20 (DIN 1.2311)

A practical buyer's guide to P20 (DIN 1.2311) pre-hardened mould steel: delivery condition, hardness range, applications and what to specify when ordering.

K

Keyspark Steel

September 19, 2026
4 min read
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Buying P20 (DIN 1.2311) is straightforward once the delivery condition, the section size and the inspection level are agreed in writing. Most problems with this grade family come from vague enquiries rather than from the steel itself.

What the grade is

DIN 1.2311 belongs to the pre-hardened plastic mould steel family. Its defining characteristic is that supplied pre-hardened in the 28 to 32 HRC range so that most moulds can be cut and put into service without a further hardening cycle. That single property is the reason engineers select it, and it should drive everything else in the purchase specification.

Typical properties

In the condition in which it is normally supplied or used, the grade is quoted as typical core hardness 28 to 32 HRC with good through-section consistency. These figures are only meaningful when they are tied to a section size, a test position and a heat treatment condition, so ask for all three.

Where it is used

The usual applications are mould base plates, cavity plates for general injection moulds and blow mould tooling. Outside these applications the grade may still work, but the reason for choosing it usually disappears and a cheaper steel will do the same job.

Heat treatment and processing

No hardening is normally required. If a cavity insert must be hardened, the steel can be austenitised around 850 C, quenched in oil and tempered, but most users buy it for its ready-to-machine condition.

What to specify when ordering

Specify the thickness, the flatness tolerance, the hardness range and the ultrasonic test level. Ask for the hardness to be measured at mid-thickness, not only on the surface.

Hubei Keyspark Special Steel Co., Ltd. runs two 20-ton EAF furnaces, two 20-ton LF ladle furnaces, a 20-ton VD unit and a 5-ton ESR furnace, with open-die forging, 12 precision heat treatment furnaces, four vacuum annealing furnaces and over twenty machining centres. Annual capacity is about 15,000 tonnes.

Website: https://keysparksteel.com/

Email: sales@keysparksteel.com

Mobile/WhatsApp: +86 15024056480Buying P20 (DIN 1.2311) is straightforward once the delivery condition, the section size and the inspection level are agreed in writing. Most problems with this grade family come from vague enquiries rather than from the steel itself.

What the grade is

DIN 1.2311 belongs to the pre-hardened plastic mould steel family. Its defining characteristic is that supplied pre-hardened in the 28 to 32 HRC range so that most moulds can be cut and put into service without a further hardening cycle. That single property is the reason engineers select it, and it should drive everything else in the purchase specification.

Typical properties

In the condition in which it is normally supplied or used, the grade is quoted as typical core hardness 28 to 32 HRC with good through-section consistency. These figures are only meaningful when they are tied to a section size, a test position and a heat treatment condition, so ask for all three.

Where it is used

The usual applications are mould base plates, cavity plates for general injection moulds and blow mould tooling. Outside these applications the grade may still work, but the reason for choosing it usually disappears and a cheaper steel will do the same job.

Heat treatment and processing

No hardening is normally required. If a cavity insert must be hardened, the steel can be austenitised around 850 C, quenched in oil and tempered, but most users buy it for its ready-to-machine condition.

What to specify when ordering

Specify the thickness, the flatness tolerance, the hardness range and the ultrasonic test level. Ask for the hardness to be measured at mid-thickness, not only on the surface.

Hubei Keyspark Special Steel Co., Ltd. runs two 20-ton EAF furnaces, two 20-ton LF ladle furnaces, a 20-ton VD unit and a 5-ton ESR furnace, with open-die forging, 12 precision heat treatment furnaces, four vacuum annealing furnaces and over twenty machining centres. Annual capacity is about 15,000 tonnes.

Website: https://keysparksteel.com/

Email: sales@keysparksteel.com

Mobile/WhatsApp: +86 15024056480

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K

Keyspark Steel

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