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How to Select the Correct Abrasive Cutting Wheels for your Metallographic sectioning and Precision cutting requirements!

How to Select the Correct Abrasive Cutting Wheels for your Metallographic sectioning and Precision cutting requirements!

Abrasive cutting wheels

Abrasive cutting wheels play a key role in ensuring that you are getting the most efficient and effective use out of your precision cutting processes. Learn what goes into matching abrasive cutting wheels. Ensure that you are making the correct selection, when it comes to choosing your abrasive cutting wheels.

High quality precise sectioning and cutting of workpieces is essential for metallographic analysis, and for any high precision metal industry. Previous posts discussed the different sectioning techniques and why abrasive cutting is the most widely used and trusted method.  

This article will discuss various aspects involved in conducting abrasive cutting for metallographic specimen preparation, and for cutting processes in high precision industries. 

Benefits of selecting the correct Abrasive Cutting Wheel for your application: 

There are many important features and aspects to consider when selecting Abrasive Cutting wheels. By making the correct selection your cutting process can make best use of the following benefits:

  • No Material Alteration 
  • Minimum heat generation, there must be no thermal burning on the surface of the specimen. 
  • Smooth clean cut, Burr Free. 
  • Specimen must give an accurate representation of the work piece being tested. 
  • Long wheel life 
  • Correct wheel Matching 

First consideration Safety

Safety is always the first consideration when dealing with abrasive cutting wheels. To ensure high safety levels follow recommended safety procedures. It is important to use cutting wheels from a manufacturer that you can trust and that manufactures to the highest quality standards. 

Always ensure the following: 

Selecting the correct Abrasive Cutting Wheel: 

When selecting an Abrasive Cutting Wheel the abrasive cutting wheel’s characteristic are some of the key factors to consider. Abrasive cutting wheels come in a variety of different: 

  • Sizes 
  • Bonds 
  • Abrasive materials 

The choice of abrasive cutting wheel will depend on the material that you are cutting. The material being cut will influence which bond and abrasive cutting material should be used. While the size of the workpiece and the required cut will influence the size of the wheel required.

A simple guideline is shown in the chart below : 

Abrasive Materials

A = Brown Aluminium Oxide – Standard abrasive used to cut ferrous metals.

WA = White Aluminium Oxide – Purified aluminium Oxide is more friable and presents sharper crystal faces during cutting, thus reducing heat generation and a better quality finish.

PA = Pink Aluminium Oxide – Chromium is added to Aluminium Oxide giving a characteristic pink colour. This gives greater hardness and toughness than White Aluminium Oxide. Pink Aluminium Oxide has sharp edges and extraordinary durability.

C = Silicon Carbide – Cutting non-ferrous metals and Cast iron.

abrasive cutting wheel selection

Wheel Hardness

Another crucial factor in selecting the correct abrasive cutting wheel is the hardness of the abrasive cutting wheel.  

characteristics of abrasive cutting wheels 1.1

Hard Cutting Wheels: 

Harder cutting wheels have a less porous bond and breakdown at a slower rate. They are designed for cutting softer metallic materials. This allows them to provide an optimum cut for softer materials. 

Soft Cutting Wheels 

Softer cutting wheels have a more porous bond and breakdown at a faster rate. This allows for more abrasive particles to become free and conduct the cutting process. These wheels are designed specifically for cutting harder metallic materials and as such provide an optimum cut. 

Bond

Rubber V Resin Bonds.

The recurring question of when to use rubber or resin bonded wheels comes down to application.

Rubber bonded wheels have an elastic bond that provides advantages for metallurgical cutting applications. Rubber bonded wheels can be produced thinner and will maintain greater structural stability at reduced thicknesses.

Resin bonded wheels are more versatile and can be used both with and without a coolant. As the bond percentage decreases in softer specifications non-reinforced resin wheels must be manufactured thicker in order to maintain stability.

Applications using a 2mm resin wheel can be substituted by a 1 to 1.2 mm rubber wheel, but coolant must be applied.

Learn more about our resin and rubber  bonded wheel ranges by visiting our precision cutting page.

Making the Correct Selection

Non-Reinforced cut-off wheels are designed without fiberglass. These wheels should only be used on a totally guarded cutting. The workpiece must be securely clamped and guarded. 

Below is an outline of a Non-Reinforced cut-off wheel and the details which are important to consider when selecting the correct abrasive cutting wheel. 

abrasive wheel markings

The Benefits of selecting the Correct Abrasive Cutting Wheel

Selecting the best abrasive cutting wheel for your specific operation will allow you to better and safer perform your cutting operations and result in the following benefits: 

  • Minimum material wastage, using the correct wheel for the material and size will allow you to reduce the amount of material wastage occurring from the cutting process. 
  • No Material Alteration, by correctly matching the material to the abrasive cutting wheel you will reduce heat generation and any resulting material alteration. 
  • Burr-free cut, the correct wheel operating under optimum conditions will ensure a burr-free cut. 
  • Smooth Finish, the correct wheel operating under optimum conditions will ensure a smoother cut, leading to a more polished finish. 
  • Longer lasting wheel life, using a wheel specifically for the material being cut will drastically improve the life expectancy of the cutting wheel. 
  • Safety & Peace of Mind, A poor choice of cutting wheel can both be dangerous to the operator and easily damage the specimen being cut and tested. 

How to request information on what cutting wheel you should be using?

We provide a wide range of resin and rubber cutting wheels with specifications that can be adjusted to match your material cutting needs for either industrial use such as cutting Inconel tubes or for preparing metallographic specimens. 

To request advice, use the button below to fill out our Online Technical Data Request Form. Please fill out the form with as much information as possible and one of our team will be in touch with our suggestions. 

Alternative you can contact us directly at: atto@attoabrasives.com or visit our request quote page on the atto abrasives website.

Product Matching & Customization

Send in your requirements and let us assist you in finding the correct product for your application.

Frequently Asked Questions

Yes, we manufacture a wide range of different sizes and specifications of abrasive cutting wheels. Send us in your requirements and we will let you know how we can help.

Rubber bonded cutting wheels are best suited for cutting with a coolant. åtto also provides a range of rubber bonded cutting wheels suitable for dry cutting. Please specify if you require cutting wheels to operate without a coolant by email: sales@attoabrasives.com  

What coolant is recommended for Rubber Bonded cutting wheels?  Rubber bonded cutting wheels are suitable for use with water and 3% soluble rust inhibitor added. Oil based coolants are not recommended.

Cutting speeds for abrasive cutting wheels vary according to section size and the material being cut. For questions relating to operating speed you can email us at : technical@attoabrasives.com

What is the maximum operating speed for rubber cutting wheels? Always check the speed specified with the wheels before use. Most rubber bonded cutting wheels are rated to 60 m/sec but special bonds are available for higher speeds.

åtto abrasives Ltd  will use all reasonable measures to ensure that the contents of this Site are accurate and up to date and does not accept any liability for any information which may not be accurate. We also reserve the right to change data, references and product specifications at any time.

Price  and availability information is subject to change without notice.

Yes, of course, send in your technical requirements to us at: atto@attoabrasives.com 

We will review your requirements and propose a wheel to fit your needs.

Note 1.1. This article does not purport to address all of the safety concerns, associated with the preparation of Metallographic specimens or the use of abrasive cutting. It is the responsibility of the individual and their company to establish appropriate safety and health practices.

Dealing with abrasives and metallic materials is always dangerous and appropriate care should be taken. Never use abrasive cutting wheels on an unguarded cutting machine.

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Preparation of Metallographic Samples & why to use abrasive cutting wheels

Preparation of Metallographic samples and why to use abrasive cutting wheels !

Sectioning

Sectioning, the preparation of metallic specimens for mounting, polishing and testing. This is required in most metallographic work. It enables the production of a sample piece that is suitable for testing and analysis purposes. This allows the test piece to be properly oberserved, documented & measured.

Care must be taken during the sectioning process in order to obtain the highest quality polished surfaces possible. The finished material can often be affected by different factors. These different factors range from alloy composition to processing conditions such as; cold working, heat treatment, and welding. 

  • Improper preparation of samples can lead to false interpretations or bad analysis. Therefore for high precision industries such as aerospace & automotive it is essential to select the most appropriate sectioning technique that works for you.

Sectioning Techniques: 

In most cases sectioning is required to get an appropriate size and shape for testing purposes. Different sectioning techniques can be used. It is important that the sectioning technique selected must not significantly alter the material characteristics. 

Some damage will inevitably occur at the cutting site. However, this damage can be minimized by applying appropriate techniques and taking care in the sectioning process. 

Different Sectioning Techniques:

  • Fracturing (The separation of an object or material into two or more pieces under the action of stress). 

Fracturing can be used to obtain samples from brittle materials such as ceramics and carbides. This process requires fracturing the test piece and then polishing the fractured test piece. 

  • Shearing (Shear cutting, the separation of a workpiece by two blades moving in opposite directions past each other). 

Shearing is a sectioning process that generates little heat, but it does produce substantial deformations and is not recommended for sensitive materials. 

  • Sawing 

Sawing does produce a rough surface, considerable heat, and deformation. 

  • Abrasive cutting (Abrasive cutting is the process of using a thin rotating disc of abrasive consumable cutting wheels to prepare a test sample). 

abrasive cutting for metallography is the most common method and most highly considered method, this is due to the wide range of materials and hardnesses which can be effectively cut, and the excellent quality of surfaces produced. 

  • Wire Saws (A fine wire is continuously drawn over the sample at a controlled pressure). 

This method is popular in the electronics industry however the cutting rates are very low. 

Key points to consider for abrasive cutting for metallography 

The quality of the abrasive cutting wheels. Always the most important feature to consider in selecting abrasive cutting wheels is safety.  

Only purchase abrasive cutting wheels from reputable manufacturers. 

  • Follow the manufacturers’ safety guidelines. 
  • Always use a totally guarded machine and never exceed the recommended operating speeds. 
  • If you have any concerns contact the manufacturer.

 

abrasive cutting wheels for metallography

Wheel Matching Advice

Wheel Matching: 

To ensure the best abrasive cutting for metallography it is important to match the work piece material to the abrasive cutting wheel. 

This is done through matching the wheel to: 

  • The material being cut:
  • Is it Ferrous or Non-Ferrous?
  • Hardness of material being cut?

The material being cut and the hardness of the material impact on the choice of abrasive material to be used in the cutting wheel. 

Finer abrasive grains create a smoother cut and are preferential for delicate work. The thinner the abrasive cutting wheel the less damage to the work piece that occurs. 

Abrasive cutting wheels can use either rubber or resin for bonding: 

  • Resin wheels are used for dry cutting 
  • Rubber wheels are used with a coolant. 

Wheel Hardness: 

Soft Wheels: 

Softer wheels have a more porous bond which permits the wheel to break down and be consumed at a faster rate. The faster breakdown allows for more of the cutting particles to be exposed. This increases the cutting process. 

Softer wheels are designed to cut hard metallic materials. 

  • It is important to note the hardness code of the abrasive cutting wheel being used and ensure that it matches with the material being cut. 

Hard Wheels: 

Harder wheels have a less porous bond and breakdown at a slower rate. They are designed for cutting softer metallic materials and as such provide an optimum cut for softer materials. 

  • It is important to note the hardness code of the abrasive cutting wheel being used and ensure that it matches with the material being cut. 

Other Considerations include but are not limited to:

  • The cutting machine being operated. 
  • Mounting, for abrasive cutting the workpiece must be mounted within a totally guarded fixed machine. 
  • Coolant or non-coolant, rubber bonded wheels are used with coolant, the coolant should be directed at the cutting spot and be even in pressure to ensure straight consistent cutting.  
  • Abrasive cutting wheel bond. Abrasive cutting wheels are designed for cutting specific materials. It is important to match the wheel hardness code to the appropriate material. 

Sectioning is required in most metallographic work. Sectioning using abrasive cutting wheels enables the production of a sample piece that is suitable for testing and analysis. Care must be taken during the sectioning process to obtain high quality polished surfaces. 

Most issues that arise in material testing can be traced back to improper care being taken when selecting and preparing a test specimen.

If you have any questions use the button below to contact us directly. Or learn more by visiting our precision cutting page

abrasive cutting wheels for metallography
åtto abrasives precision cutting wheels
abrasive cutting wheels for metallography
åtto abrasives precision cutting wheels

Frequently Asked Questions

Yes, we manuafcture a wide range of different sizes and specifications of abrasive cutting wheels. Send us in your requirements and we will let you know how we can help

Rubber bonded cutting wheels are best suited for cutting with a coolant. åtto also provides a range of rubber bonded cutting wheels suitable for dry cutting. Please specify if you require cutting wheels to operate without a coolant by email: sales@attoabrasives.com  

 

What coolant is recommended for Rubber Bonded cutting wheels?  Rubber bonded cutting wheels are suitable for use with water and 3% soluble rust inhibitor added. Oil based coolants are not recommended.

 

For a more extensive education of metallographic techniques, you could refer to Samuels, L.E., Metallographic Polishing by Mechanical Methods, American society for Metals 3rd edition.

Cutting speeds for abrasive cutting wheels vary according to section size and the material being cut. For questions relating to operating speedm you can email us at : technical@attoabrasives.com

What is the maximum operating speed for rubber cutting wheels?Always check the speed specified with the wheels before use. Most rubber bonded cutting wheels are rated to 60 m/sec but special bonds are available for higher speeds.

åtto abrasives Ltd  will use all reasonable measures to ensure that the contents of this Site are accurate and up to date and does not accept any liability for any information which may not be accurate. We also reserve the right to change data, references and product specifications at any time.

Price  and availability information is subject to change without notice.

Note 1.1. This article does not purport to address all of the safety concerns, associated with the preparation of Metallographic specimens or the use of abrasive cutting. It is the responsibility of the individual and their company to establish appropriate safety and health practices.

Dealing with abrasives and metallic materials is always dangerous and appropriate care should be taken. Never use abrasive cutting wheels on an unguarded cutting machine.