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What are the hardest materials for the most challenging applications?

CNC machined parts meant for hardworking industrial conditions often need to exhibit exceptional durability, resistance to corrosion, and high mechanical strength. This means choosing the right material is paramount. In this article, we’ll take a look at a few of the hardest materials our customers use for the hardest applications. We’ll also explore various types of strength, their benefits, and the materials best suited to providing them.

What is material “hardness” in CNC manufacturing?

In the context of materials science, "hardness" typically refers to the material's ability to withstand indentation, scratching, or other forms of surface penetration when subjected to mechanical forces or abrasive conditions. Hard materials are less likely to undergo wear, deformation, or damage, making them suitable for applications where durability is essential.

Hardness and strength – what is the difference?

Hardness and strength are different properties. Hardness is the resistance of a material to indentation or abrasion on the external surfaces, while strength is the ability to withstand an applied load without failure or permanent deformation. Materials can also be treated in various ways to improve their strength and/or surface hardness. These are the most common categories of material strength.

  • Compressive strength. This property indicates the maximum load a material can endure in compression before collapsing. Manufacturers often consider compressive strength when designing components that must support heavy loads in industrial machinery and equipment.

  • Tensile strength. Tensile strength represents the maximum stress a material can withstand while being pulled before it breaks. It is crucial in manufacturing applications subjected to high degrees of tension, such as hanging tools, wires, cables, and structural elements for buildings and bridges. 

  • Yield strength. Yield strength helps manufacturers understand a material's limit before it undergoes permanent deformation. It is significant for metal components that must maintain their shape and structural integrity, such as those intended for load-bearing applications.

  • Impact strength. This property indicates how well a material can resist fractures or breakage when subjected to sudden forces, dynamic loads, or impact. Manufacturers rely on materials with high impact strength for producing durable parts used in machinery, tools, and automotive components.

What are the hardest materials for CNC manufacturing?

Here are a few materials that industrial customers often use to create parts or components meant for hardworking environments. 

  • Tungsten. Has a high melting point, tensile strength, a decent hardness, and low thermal expansion. Tungsten is used in high-temperature applications. It is brittle at room temperature and can be challenging to machine.

  • Chromium. Offers high hardness, corrosion resistance, and wear resistance. Because pure chromium is brittle, it is best used as an alloy and in the production of stainless steel

Best practices for improving material hardness  

By following these best practices, you can take steps toward enhancing material hardness. Properly hardened materials can withstand higher stresses, resist wear, and maintain structural integrity, reducing the risk of failure and costly replacements. Additionally, compliance with these practices can be a legal requirement in regulated industries.

  • Alloying. Incorporating alloying elements, such as chromium, molybdenum, or vanadium, into the material composition can increase hardness.

  • Cold working. Cold working is a manufacturing process where a material is deformed or shaped at room temperature or below, increasing its strength and altering its mechanical properties without heating.

  • Thermochemical treatments. Techniques like carburizing or nitriding can harden the surface of materials, improving wear resistance.

Precise machining. Using appropriate cutting tools and techniques, as well as slower cutting speeds during machining can help maintain hardness, avoid overheating and softening the material.

Find out more about selecting materials for CNC machining, 3D printing and injection molding. You can also read more about material properties on our Knowledge Base. For pricing and lead times for your custom parts, upload a CAD file to our quote builder. 


CNC machining, 3D printing and sheet metal fabrication parts

Frequently asked questions

What are hard materials in CNC machining?

Hard materials are those that can withstand indentation, scratching, or other forms of surface penetration when subjected to mechanical forces or abrasive conditions.


How does cutting speed affect machining hard materials?

Slower cutting speeds are usually required for hard materials to prevent excessive tool wear.


What are common applications for CNC machining hard materials?

Aerospace and automotive components, heavy machinery, medical implants, and high-performance tools often use hard materials.


What are the benefits of machining hard materials?

Machining hard materials can result in components with excellent wear resistance, durability, and precision.

 

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