For grinding concrete and metal use grinding disk.

Try a diamond tuckpointing wheel to remove mortar.

For cutting metal sheets, pipe, tile, masonry, and wire use a cutting disk.

To remove rust and paint use brushing wheels.

Ceramic or white aluminum oxide disks are available for cutting and grinding harder steels such as stainless steel.

Diamond coated disks can be used for cutting brick, stone, concrete, slate and roof tiles.

These are a relatively new innovation and similar to disks used for cutting masonry. The edge of the disk is coated with diamond particles. These have three major advantages over traditional bonded abrasive disks: 

• The disk is steel and much less likely to shatter.
• No use-by date issues unlike bonded abrasive disks.
• Cutting doesn't produce sparks.

Thinner disks are used for cutting metal sheeting such as roof cladding. These cut quicker with less friction so there's less damage to protective coating/paint on sheets. However, they also wear away somewhat quicker.

When attaching your disc, check the specification. The max RPM on the disc should meet or exceed the max RPM of the angle grinder you plan to use. If the rated speed of the disc is lower than your grinder, chances are that the wheel would fly apart.

Unlike drill motors that run at about 700 to 1,200 rpm, grinders spin at a breakneck speed of 10,000 to 11,000 rpm. They’re fast enough to be scary! As angle grinders can quickly remove lots of material, sparks are created too. Put on safety gear like goggles, long sleeves, and full-face protection. You can lower the risk as much as possible by positioning the tool properly. Your chances of getting injured can be reduced if you ensure that sparks and debris fly away from your body. What’s more, the lifespan of your work clothes will be longer!

It is not a good idea to stop the disc before you’re completely done because the disc can stick in the material. Let the part you’re cutting fall on the ground and stop the tool then. The part will be hot so let it cool down for a few minutes before touching it.

This can overload the power tool. Instead, angle the grinder so that sparks are thrown in a different direction from you, and allow the tool to develop maximum speed and press it gently onto the material you’re cutting. Keep the disc on 90 degrees all the time and avoid twisting it because it can bend or break.

This may come as strange to you, but did you know that discs have an expiration date too? This is because moisture and rust can damage the disc.

Hit the power button to turn it on. Whether you're cutting, grinding, or sanding, allow it to come up to speed to help you keep your actions smooth and consistent. For instance, if you're cutting through metal or other materials, you'll get a better cut if the cutting disc is at full speed first.

For sanding, apply the tool at a 5°-10° angle to the work surface.[13] For grinding, try a 15°-30° angle; make sure you're using the flat part of the wheel when using this attachment.

The guard may get in the way on some projects, but don't take it off. It provides some protection from flying debris if the wheel or attachment shatters. It's much better for the guard to take the hit then your torso or arms!

If the wheel is still spinning, it can move around on the surface you set it on. Apply the braking system of  DEKO angle grinders and you don't need to wait for it to come to a full stop.