Description

1.2311 Steel Plate (310 × 160 mm) / DIN 40CrMnMo7 / AISI P20 / SAE P20

Link: 1-2311-steel-plate-310x160

1.2311 Steel Plate (310 × 160 mm), also known as DIN 40CrMnMo7, AISI P20, and SAE P20, is a premium pre-hardened plastic mould steel manufactured for high-performance tooling and industrial mould applications. It offers an excellent combination of toughness, wear resistance, dimensional stability, and machining performance, making it one of the most preferred mould steels in the tooling industry.

Manufactured to international quality standards, this steel is supplied with consistent mechanical properties and can be provided with quality inspection reports and material test certificates. Its pre-hardened condition reduces machining time and eliminates the need for additional heat treatment in most standard mould manufacturing applications.

Equivalent Designations

Standard	Grade
AFNOR	40 CMD 8
UNI	35 CrMo 8 KU
DIN	40CrMnMo7
AISI / SAE	P20

Chemical Composition

Element	Content (%)
Carbon (C)	0.40
Silicon (Si)	0.40
Manganese (Mn)	1.50
Chromium (Cr)	1.90
Molybdenum (Mo)	0.20

Mechanical Properties

Hardness

• 280–325 HB
• Approx. 950–1100 N/mm² tensile strength

Thermal Conductivity

• 35 W/m·K at 100°C

Material Characteristics

• Pre-Hardened Alloy Tool Steel
• Excellent Dimensional Stability
• High Toughness
• Good Wear Resistance
• Excellent Machinability
• Superior Surface Finish
• Suitable for Polishing
• Suitable for Nitriding
• Reliable Mechanical Performance
• Long Service Life

Applications

• Plastic Injection Mould Cavities
• Mould Inserts
• Plastic Mould Bases
• High-Strength Machine Components
• Industrial Tooling
• Precision Engineering Parts
• Die Sets
• Heavy-Duty Mechanical Components

Surface Treatment Options

Etching

• Suitable for precision engraving and surface texturing.

EDM (Electrical Discharge Machining)

• Excellent response for machining complex mould cavities.

Polishing

• Provides excellent mirror-finish polishing for high-quality mould surfaces.

Nitriding

• Improves surface hardness and significantly enhances wear resistance.

Hard Chrome Plating

• Increases both wear resistance and corrosion protection while extending mould service life.

Heat Treatment

Pre-Hardened Condition

• Normally supplied ready for machining; additional heat treatment is generally not required.

Stress Relief Annealing

• Recommended at 580°C before nitriding to reduce internal stresses.

Hardening

• Heat uniformly to 840–860°C.

Cooling

• Cool in an oil or hot bath to 180–220°C, then allow air cooling to approximately 100°C.
• Achievable hardness: Up to 52 HRC.

Tempering

• Temper immediately after hardening.
• Minimum holding time: 1 hour for every 25 mm of section thickness to achieve the desired balance of hardness and toughness.