ThePipingMart Blog Grades M43 Tool Steel (T11343) – Composition, Properties, and Uses

M43 Tool Steel (T11343) – Composition, Properties, and Uses

Tool Steel M43

Tool Steel M43 is a high-speed steel alloy with exceptional wear resistance and hot hardness. It has an excellent red hardness, making it ideal for use in applications requiring cutting tools that must remain sharp and durable at high temperatures. Tool Steel M43 is also corrosion-resistant and offers excellent machinability and weldability. Let’s take a closer look at this versatile steel alloy.

M43 Tool Steel Composition

M43 Molybdenum High Speed Tool Steel contains 4% tungsten, 4% chromium, 1.5% vanadium, 0.45% cobalt, 0.35% molybdenum, 0.2% silicon, and 0.2 % manganese in addition to carbon and iron as its main components. This combination of metals makes it an ideal choice for metalworking applications that require superior heat resistance, wear resistance, and hardness such as those found in the aerospace industry or automotive industry.

Element Weight %
C  1.15-1.25
Mn  0.20-0.40
Si  0.15-0.65
Cr  3.50-4.25
Ni  0.3
Mo  7.50-8.50
W  2.25-3.00
V  1.50-1.75
Co  7.75-8.75
Cu  0.25
P  0.03
S  0.03

M43 Tool Steel Chemical Properties

Tool steel M43 is extensively used for machining and construction due to its combination of high strength, good hardenability, and accessibility from many suppliers. Its chemical properties make it especially useful for various applications requiring extreme corrosion resistance. Not only does M43 offer superior toughness and wear resistance, but it’s easy to machine and has great dimensional stability when heat treated to the desired hardness. With characteristics like great weldability as well, it’s no wonder tool steel M43 is one of the most popular materials available today.

M43 Tool Steel Physical Properties

Tool steel M43 is an alloy that combines various physical properties to create a strong and workable material. It has good thermal and impact stability, making it ideal for industries with highly demanding tasks. It also has a relatively easy machinability compared to other steel alloys. With the addition of the element cobalt, its overall strength and hardness are improved significantly. Furthermore, tool steel M43 has an exceptional abrasion resistance making it resilient against wear and tear caused by general use. These characteristics make this alloy a desirable choice within industries regularly utilizing high-powered tools, such as aerospace or automotive sectors.

M43 Tool Steel Mechanical Properties

Tool Steel M43 has a number of impressive mechanical properties that make it suitable for a variety of uses, including its ability to maintain a sharp cutting edge even after being subjected to high temperatures, its superior corrosion resistance and its excellent machinability, which can make it easier to work with than other types of steel alloys.

Properties  Conditions
T (°C) Treatment
Density (×1000 kg/m3) 7.7-8.03 25
Poisson’s Ratio 0.27-0.30 25
Elastic Modulus (GPa) 190-210 25

M43 Tool Steel Uses

Tool steel M43 is a high-speed steel with the perfect combination of superb wear resistance and red hardness. These properties make it an ideal material for cutting tools that machine aluminium, copper, magnesium and other ductile non-ferrous materials at increased speeds and improved quality. Its use can be found in modern machining centers that require quick changeover between different applications such as drilling, reaming and tapping. Moreover, tool steel M43 has also seen wide application in cutting cold heading dies and form rolls used in heavy forging applications. Therefore, its versatility makes it one of the most preferred materials for machining various parts across multiple industries.

Corrosion Resistance

Tool steel M43 has a range of unique properties, making it attractive for use in various industrial applications. It is renowned for its high corrosion resistance capabilities; with the addition of Nickel and small amounts of Chromium and Molybdenum, it creates an alloy that is resistant to harsh elements as well as heat and wear. These qualities make it suitable for components that require greater durability over longer periods in conditions where other steels may be prone to corrosion or frequent breakdowns. Additionally, M43 offers superior hardness and boasts good fatigue strength, meaning that it proves very beneficial for jobs such as rock drilling or creating moulds where multiple operations are required. Yet, a high level of durability must be maintained. Ultimately, tool steel M43 can provide businesses with a robust solution specially tailored to their production needs.

Heat Resistance

This type of steel alloy is also highly resistant to impact damage thanks to its strong tensile strength, making it an ideal choice for applications involving heavy machinery or tools that will be subject to frequent contact with other materials or objects during operation.

Heat Treatment

Tool Steel M43 can be hardened by heat treating or through induction hardening processes depending on the desired outcome for the application in question. In order to increase the strength of Tool Steel M43 while still preserving its wear resistance and toughness, welding may be required depending on the application’s needs as well as any other factors, such as environmental conditions or material properties that might affect how well the welded piece holds up over time.


In general, however, Tool Steel M43 is considered easy to weld due to its low level of carbon content which helps reduce warping during the welding process compared with other types of steel alloys that contain higher levels of carbon content which can cause issues if not properly preheated before welding begins.


Machining tool steel M43 can be a challenging yet immensely rewarding experience. It is an alloy steel meant for applications requiring great tools to handle extreme wear and fatigue, such as for cutting tools and injection moulds. Its ideal combination of high strength and outstanding toughness requires the right machining techniques in terms of advanced technology or know-how from able machinists. For any entity that requires machining of tool steel M43, it is essential to have an experienced team at the helm to guarantee proper outcome. With the right process and personnel knowledge, one can enjoy the excellent results that a successful project can deliver, making it more than worth it in the end.


Whether you’re looking for superior wear resistance, heat treatment capability, or need an alloy that’s easy to machine and weld when necessary – Tool Steel M43 should fit your requirements perfectly! Its combination of metals makes it incredibly versatile, allowing you to use it in many different industries, from automotive manufacturing, where heat treatment and durability are key considerations, all the way through aerospace engineering, where weight savings are essential – meaning this type of tool steel really does have something for everyone!

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