1.2311 | 40CrMnMo7 | stal 1.2311 | Pre-Hardened Plastic Mold Steel Supplier

1.2311 is a premium chromium-manganese-molybdenum plastic mold steel manufactured to DIN EN ISO 4957 standards. As the German equivalent of AISI P20, 40CrMnMo7 and 3Cr2Mo, what sets it apart is its ready-to-use pre-hardened condition (280-325 HB). This eliminates the need for post-machining heat treatment and the risk of distortion, significantly reducing manufacturing lead times and production costs for mold makers.

This pre-toughened steel offers an excellent balance of good machinability, moderate wear resistance, and reliable toughness. Its through-hardened structure ensures uniform properties—ideal for large mold bases and cavity plates. Whether for plastic injection molds, zinc die casting dies, mold frames, or high-tensile machine parts, it delivers consistent performance. Supplied pre-hardened for immediate machining or annealed for custom heat treatment.

Material Shape and Size of 1.2311

1. 1.2311 Steel Round Bar

2. Flat Bar

1.2311 Equivalent

Standard System

Country/Region

Equivalent Grade

Common Search Terms

DIN EN

Germany

1.2311, 40CrMnMo7

1.2311 steel, DIN 1.2311, 40CrMnMo7, 1.2311 material

AISI/ASTM

USA

P20

P20 tool steel, AISI P20, P20 mold steel

AFNOR

France

40 CMD 8

40 CMD 8 steel

China

3Cr2Mo

3Cr2Mo steel, GB 3Cr2Mo

UNI

Italy

35 CrMo 8 KU

Italian standard equivalent

ISO

International

40CrMnMo7

ISO 1.2311 equivalent

1.2311 Chemical Composition

Element	C	Si	Mn	P	S	Cr	Mo
Content (%)	0.35-0.45	0.20-0.40	1.30-1.60	≤0.035	≤0.035	1.80-2.10	0.15-0.25

Note: The defining feature of 1.2311 tool steel is its balanced chromium-manganese-molybdenum composition, which provides excellent through-hardening properties and uniform hardness distribution in large sections . The moderate carbon content ensures good machinability while maintaining adequate strength for mold applications .

Mechanical Property of 1.2311 material

MECHANICAL PROPERTY	METRIC VALUE	IMPERIAL VALUE
Hardness (Annealed)	≤230 HB	≤230 HB
Hardness (Quenched & Tempered)	28-34HRC	28-34HRC
Tensile Strength (σb)	965 – 1030 MPa	140 – 149 ksi
Yield Strength (σ0.2)	827 – 862 MPa	120 – 125 ksi	%
Elongation (δ5)	20 %	20 %

Delivery Condition of 1.2311

Black Surface, Bright Surface, Turned Surface, Grinded Surface, Poblished surface.

1.2311 Application

Plastic Mold Industry: Injection mold cavities and cores for general-purpose plastics, mold frames and bases, support plates, holder blocks, large injection molds for household appliances and automotive components
Die Casting Tools: Zinc die casting dies, pressure casting dies for non-ferrous alloys, recipient sleeves for die casting machines
Mold Components: Backers, bolsters, die holders, shoe blocks for plastic pressure dies, hydroforming mold tools
Mechanical Engineering: High-tensile machine parts, shafts, rails, wear strips for industrial equipment
Automotive Industry: Prototype molds, production tooling for interior trim components, lamp housings, and dashboard parts requiring good surface finish
Consumer Goods: Molds for household products, appliance housings, and packaging components where moderate wear resistance is sufficient
Extrusion Tooling: Extrusion dies for plastic profiles, blow molding tooling components requiring good thermal conductivity

Heat Treatment & Processing of 1.2311 Steel

Heat Treatment:

Soft Annealing: Heat to 710-740°C, cool slowly in furnace. Resulting hardness ≤230 HB, optimized for extensive machining operations
Stress Relieving: Heat to approximately 580-650°C, hold 1-2 hours per 25mm section, slow cool. Relieves machining stresses to minimize distortion during final processing or before nitriding
Preheating: Recommended at 400-600°C for complex parts before hardening operations
Hardening (Austenitizing): Temperature 830-880°C, soak time proportional to section size. Protect against oxidation and decarburization
Quenching: Oil quench (40-60°C) for most sections; warm bath quench at 180-220°C; air quench possible for smaller sections. Quench to 50-70°C, then temper immediately. Hardness after quenching: 51-52 HRC
Tempering: Temper immediately after quenching while tool is still warm. Hold minimum 1 hour per 25mm section thickness. Cool slowly to room temperature.

Processing Guide:

Nitriding: Gas nitriding at 525°C in ammonia gas achieves surface hardness 600-700 HV with case depth 0.30-0.50mm depending on treatment time . Soft nitriding (Tufftriding) at 570°C for 2 hours achieves surface hardness approximately 700 HV with case depth 0.01mm . Nitriding increases both wear resistance and corrosion resistance
Hard Chrome Plating: After chrome plating, anneal at 180°C for 3-4 hours to avoid hydrogen embrittlement
Forging: Hot forming temperature 1050-850°C, do not forge below 850°C. After forging, slow cool in furnace or insulating media to prevent cracking
EDM (Electrical Discharge Machining): Suitable for wire-cut EDM; remove white layer after machining for optimal surface finish

Quality Inspection & Control of 1.2311

Full-process control of 1.2311: Raw material inspection (certificate, composition); production inspection (composition, mechanical properties, 100% UT, dimensional, surface); finished product inspection (MTC EN 10204 3.1, reports).

Our Advantages

Strong Production Capacity: 10,000 tons/year, advanced equipment.
Adequate Stock: 600+ tons standard specs (3-7 days delivery); custom specs 15-30 days.
Custom Processing: One-stop sawing, milling, drilling, polishing, heat treatment.
Strict Quality Control: Full-process inspection, professional team/equipment.
Global Supply: Container/LCL shipment, anti-rust packaging, on-time delivery.
Professional Technical Support: Senior engineers guide material selection, heat treatment, processing.