Cutting hard materials such as marble, granite, asphalt, concrete or tiles requires the use of a diamond blade. But how to choose one that will last for a long time and will deliver optimal cutting performance?
Firstly, you need to know the basics of a diamond blade.
About the design of a diamond blade
Each diamond blade forms a metal carrier (the largest visible part of the disc) and the so-called segments that are welded on this carrier. The segments are most often laser welded or sintered to the disc carrier. The less common method is to use a classic silver solder.
While the metal carrier is not particularly interesting in terms of blade quality, the composition of the segment is absolutely crucial.
The segment consists of a binder (called a matrix) and synthetic diamond granules that appear to be randomly distributed in this binder. And it is precisely the frequency, size and shape of diamond grains in the binder that fundamentally determine the life and cutting properties of the blade.
During cutting with a diamond disc, the segment of the binder and the diamonds are evenly worn. As both parts of the segment wear out simultaneously, new diamond grains are gradually exposed. Until the entire segment is consumed. You must then replace the diamond blade.
Full Frame vs. segmented
Already at the first glance of diamond discs, you will notice that some have a full-circumference segment (the segment is entirely composed of one piece, uninterrupted) and some are intermittent (gaps between the segments).
The full-circumference discs with continuous segment are suitable for cutting very hard materials such as granites, ceramics, glazed tiles. Their biggest advantage is a smooth and clean cut, with no chipped edges. The downside is that they heat up quickly and you need to cool them a lot.
Segment wheels, ie with intermittent segment, are used for cutting less hard building materials – concrete, reinforced concrete, asphalt, marble, masonry, stone, etc. The disadvantage of these discs is a slightly coarser cut, the advantage is faster cutting, better cooling and removal of the grinded material out of the cut. You can also cut the segment discs dry – without the need for water cooling, but the blade is much dustier and worn out faster.
You will also encounter turbo wheels on the market, combining both previous variants. Although the segment is all around the circumference of the diamond blade, it has small grooves on the sides that separate it. These grooves are laterally offset so that there is no gap between them. These blades cool well and carry material while delivering acceptable cut quality.