In the domain of high-performance tooling, few materials have earned the trust and widespread usage of H13 tool steel. As hot work steel alloyed primarily with chromium, molybdenum, and vanadium, H13 has become the gold standard for tooling in hot forging, die casting, extrusion, and injection moulding industries.

At Behari Lal Engineering, where metallurgical precision meets industrial reliability, we understand the value of this alloy—not just by specification, but by behaviour under stress, wear, and extreme thermal cycles. This blog delves into the properties, performance, and applications of H13 (DIN 1.2344 / SKD61) steel.

What is H13 Tool Steel?

H13, also known by international equivalents such as DIN 1.2344, SKD61, and X40CrMoV5-1, is a chromium-molybdenum hot work tool steel. Its claim to fame lies in its unique balance of thermal fatigue resistance, hot hardness, and abrasion resistance—making it ideal for moulds and dies operating at elevated temperatures.

H13 belongs to the air-hardening tool steel family and is extensively used for:

• Injection and compression moulds
• Die casting dies for aluminium and magnesium
• Extrusion dies and hot shear blades
• Forging dies, mandrels, and inserts

Key Properties of H13 Tool Steel

The performance of H13 stems from its alloy chemistry and its response to heat treatment. Here’s an improved and concise table summarizing its key mechanical and thermal properties:

Table: Technical Properties of AISI H13 Tool Steel

Property	Value / Range
Density (at 20°C)	7.8 g/cm³
Melting Point	1427°C
Tensile Strength	1590 MPa
Yield Strength	1380 MPa
Reduction of Area	50%
Elastic Modulus	215 GPa
Poisson’s Ratio	0.3
Thermal Conductivity	17.6 W/m·K
Coefficient of Thermal Expansion	10.8 × 10⁻⁶ /K
Machinability	55% (Relative to W1 tool steel)
Hardness (HRC, after tempering)	Up to 56 HRC (varies by tempering temp)

Heat Treatment and Hardness Response

H13 steel responds exceptionally well to heat treatment, which allows it to attain a wide range of hardness and toughness depending on the operating temperature. The table below illustrates how tempering temperature affects hardness:

Table: Hardness vs. Tempering Temperature for H13

Tempering Temperature (°C)	Hardness (HRC)
100	54
210	53
300	53
400	55
500	56 (Peak Hardness)
550	54
600	51
650	43
700	34

Tempering around 500°C delivers the optimal combination of hardness and toughness, ideal for most die-casting and forging applications.

Chemical Composition of H13 Tool Steel

Table: AISI H13 Chemical Composition

Element	Percentage (%)
C	0.45
Cr	5.5
Mo	1.75
V	1.2
Si	1.2
Ni	0.3
Mn	0.5
Cu	0.25
P	0.03 (max)
S	0.03 (max)

Applications of H13 Steel

Owing to its exceptional high-temperature properties, H13 is found in nearly every toolshop and foundry environment:

• Injection Molds & Dies
  Ideal for complex mould cavities and multi-cavity dies that operate under cyclic thermal loads.
• Extrusion Dies & Mandrels
  Maintains geometry and surface quality under the abrasive action of hotflowing metal.
• Hot Forging Dies
  High thermal shock resistance makes it reliable under repeated high-pressure impact.
• Die-Casting Dies
  Preferred for aluminium and zinc alloys due to excellent thermal conductivity and wear resistance.
• Plastic Molds & Punches
  Works well in precision plastic mould tools where polishability is critical.

Pros and Cons of AISI H13

Advantages

• Excellent combination of hardness and toughness
• Superior thermal fatigue resistance
• Good polishability and machinability
• Suitable for hot and cold work tooling
• Withstands repeated thermal cycling

Limitations

• Moderate corrosion resistance — not suited for aggressive environments
• Requires precise heat treatment to unlock full performance
• Limited weldability — prone to cracking without careful procedure
• More expensive than some general-purpose tool steels

Equivalent Grades Around the World

Country	Standard	Equivalent
USA	AISI/SAE	H13
Germany	DIN/WNr	X40CrMoV5-1
Europe	EN	X40CrMoV5-1
China	GB	4Cr5MoSiV1
Japan	JIS	SKD61
South Korea	KS	STD61
Russia	GOST	4Ch4VMFS
India	IS	XT35CrMoV1ST

Final Thoughts

H13 tool steel remains a cornerstone in hot work tool applications, and at Behari Lal Engineeringwe ensure that every batch of H13 meets stringent quality standards—chemically, structurally, and mechanically.

Whether you're forging precision automotive parts, die-casting components, or shaping high-performance moulds, H13 gives you the thermal strength, hardness, and life cycle reliability your application demands.

Looking for reliable H13 tool steel from the best steel company in India?

Partner with Behari Lal Engineering for engineered excellence, every time.