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tem Code: H13

M2 Molybdenum High Speed Tool Steel

Description : M2 is a general purpose molybdenum high speed steel. This grade is characterized by balanced Combination of abrasion resistance, toughness and good red hardness. Due to its comparatively low Carbon content, M2 has an excellent combination of toughness properties and abrasion resistance When properly hardened and tempered. M2 is used in a wide used for all kinds of cutting tool, knife and punch and die applications.

Molybdenum high speed steels are designated as Group M steels according to the AISI classification system. Over 95% of high-speed steels manufactured in the US are group M steels. Tungsten is present in all types from M1 to M10, except M6, and cobalt is not present in any these steels. Molybdenum high speed steels have similar performance when compared to tungsten high-speed steels. However, the initial cost of molybdenum tool steels is lower. Titanium nitride, titanium carbide and several other coatings can be used in the tools made of this kind of steels through physical vapor deposition process to improve the performance and life span of the tool.

Chemical composition Physical Properties

The physical properties of M2 molybdenum high speed tool steel are given in the following table.

Mechanical Properties

The mechanical properties of M2 molybdenum high speed tool steel are tabulated below

Thermal Properties

The following table shows the thermal properties of M2 molybdenum high speed tool steels.

Other Designations

Other designations that are equivalent to M2 molybdenum high speed tool steels include:
• AFNOR 06-05-04-02
• DIN 1.3343
• UNI KU
• JIS SKH9
• SS 2722
• B.S. BM 2
• FED QQ-T-590
• ASTM A597 (CM-2)
• ASTM A600
• SAE J437
• SAE J438
• UNS T11302

Tungsten high-speed tool steels are designated group T steels according to the AISI classification system and range from T1 to T15. These steels have similar characteristics to those of molybdenum high-speed tool steels. The following sections will discuss T5 tool steels in more detail.

Chemical composition Title

The following table shows the thermal properties of T5 tool steels.

Physical Properties

The physical properties of T5 tool steels are given in the following table.

Mechanical Properties

The mechanical properties of T5 tool steels are tabulated below.

Forging

M42 molybdenum high speed tool steel is preheated to 871°C (1599°F) in a slow manner and then soaked. This is followed by rapid heating to 1093°C (1999°F) and slow cooling. Temperatures below 982°C (1799°F) are not suitable for the forging process.

Other Designations

Other designations that are equivalent to T5 tungsten tool steels include:

• DIN 1.3265
• UNI KU
• JIS SKH 4A
• B.S. BT 5
• ASTM A600
• FED QQ-T-590
• SAE J437
• SAE J438
• UNS T12005

M35 HIGH SPEED STEEL

M35) 5% Cobalt tool bits are designed for heavy duty machining alloy steels and tough materials, such as castings and forgings. They have high heat and abrasion resistant properties and are best used when making heavy cuts, at high speeds and feeds, or where high heat is a factor.

Chemical composition Mechanical Properties

The mechanical properties of M35 molybdenum high speed tool steels are tabulated below.

Physical Properties Thermal Properties

The following table shows the thermal properties of M35 molybdenum high speed tool steels.

PROPERTY

Cobalt added M2 high speed steel in which the cobalt addition provides hot hardness, The improved hot hardness makes the steel suitable for machining high-strength and prehardened steels, high-hardness alloys

Applications

Used in conditions where the demand for hot hardness is important. 

HEAT TREATMENT

Chromium hot-work tool steels are designated as group H steels according to the AISI classification system. This series of steels start from H1 to H19. The most commonly used chromium hot-work steels are H11, H12, and H13, which can be air hardened in 150 mm thick sections. The steels are subjected to minimal distortion during hardening due to their balanced alloy content. The tools produced from chromium hot-work steels can be cooled using water without damage as these steels have low carbon and alloy contents.

This article will give an overview of H11 chromium hot-work steels, which have low carbon content and good toughness. These steels can be deep hardened by heat treatment and air-quenching.

Chemical Composition Physical Properties

The physical properties of H11 tool steels are given in the following table.

Mechanical Properties

The mechanical properties of H11 tool steels are tabulated below

Thermal Properties

The following table shows the thermal properties of H11 tool steels.

Other Designations

Other designations that are equivalent to H11 tool steels include

Chromium hot-work tool steels are designated as group H steels according to the AISI classification system. This series of steels start from H1 to H19. The most commonly used chromium hot-work steels are H11, H12, and H13, which can be air hardened in 150 mm thick sections. The steels are subjected to minimal distortion during hardening due to their air-hardening and balanced alloy content. The tools produced from chromium hot-work steels can be cooled using water without damage as these steels have low carbon and alloy contents.

This article will give an overview of H13 chromium hot-work steels, which contain strengthening agents such as vanadium and molybdenum. These steels are resistant to softening at elevated temperatures due to the presence of chromium content.

Chemical Composition

The following table shows the chemical composition of H13 tool steels.

Physical Properties

The physical properties of H13 tool steels are given in the following table

Mechanical Properties

The mechanical properties of H13 tool steels are tabulated below.

Thermal Properties

The following table shows the thermal properties of H13 tool steels.

Other Designations

Other designations that are equivalent to H13 tool steels include:

• AFNOR Z 40 COV 5
• DIN 1.2344
• UNI KU
• JIS SKD61
• SS 2242
• B.S. BH 13
• ASTM A681
• FED QQ-T-570
• SAE J437
• SAE J438
• SAE J467
• UNS T20813
• AMS 6408

Heat Treatment

H13 tool steels are preheated to 816°C (1500°F). Then the steels are directly heated by increasing the temperature to 1010°C (1850°F) followed by holding for 15 to 40 mins. The steels are then air-quenched.

Forging

H13 tool steels are forged at 1079°C (1975°F). For this type of steels, forging below 898°C (1650°F) is not preferable.

Annealing

H13 tool steels are annealed at 871°C (1600°F) and slowly cooled at 4°C (40°F) in the furnace.

Tempering

Tempering is carried out in H13 tool steels from 538 to 649°C (1000 to 1200°F) to obtain Rockwell C hardness of 53 to 38. Double tempering can also be performed in these steels for every one hour at the preferred tempering temperature.