What is a diamond cutting disc?

A diamond cutting disc is a cutting tool for use with manual machines, normally for dry cutting, and is also used in workbench mounted applications or with water for wet cutting. It is called a "diamond disc" because the segments are manufactured from alloys of synthetic diamond with different metals (cobalt, nickel, iron and tungsten carbide). The type of alloy used determines the hardness and durability of the disc. The edge of the disc, known as the segment, exists in different forms: segmented, continuous, turbo, or turbo segmented. These segments are normally sintered (brazed) or laser welded to the core of the disc.

What is the difference between wet-cutting and dry-cutting?

Diamond discs for dry cutting are used at higher RPM and are air-cooled. For this reason dry cutting discs normally measure between 100mm and 230mm in diameter in order to avoid overheating. Diamond discs for wet cutting are used with water-cooled machines at lower RPM and normally measure a minimum of 300mm in diameter.

What happens if I have been using a disc to cut different materials and suddenly find that it no longer works?

What has probably happened is that you have been cutting material which is not suitable for the disc you have used. This material will have deposited a film on the segment which blunts the disc. In order to be able to resume use of this disc, you can sharpen it by making several cuts in an abrasive material and then allowing the disc to air-cool.

The segments of the diamond disc have cracks or become separated. Why is this happening?

This generally happens when you are using a disc with a hard composite segment on material which is itself very hard. Remember that a soft segment must be used for cutting hard materials in order to avoid rebound and possible breakage of the segment.

What does the maximum speed (R.P.M) which appears on the disc mean?

This is the maximum speed at which the disc should be used in order to avoid damage to the material and overheating of the disc. It is very important to respect the recommended maximum speed (stamped on the disc) when using Lukia cutting and grinding discs. Please find below a grid with the recommended maximum speed and RPM for the most common diameters of discs.

Diameter (mm)           Maximum speed         Maximum RPM
                                        Recommended m/s         
   115                                              80                             13300        
   125                                              80                              12200
   180                                              80                                 8400
    230                                             80                                 6600
    300                                           100                                5100
    350                                           100                                4300
    400                                           100                                3800
    450                                           100                                3400
    500                                            100                               3100

What do "sintered" or "brazed" mean?

This term refers to the system used to weld the segments to the core of the disc. It is a kind of weld using a silver alloy, typically used for low-mid range discs. At Lukia, these discs are called the Plus series.

Can the complete segment become detached?

In some cases, where hard material is being cut without cooling, the segment can heat up so much that it becomes detached. The disc normally breaks where the segment is joined to the core of the disc, ie. the weld. In the case of discs incorporating laser welds, the entire segment will become detached.