The bond (or metal matrix) is what keeps the diamonds in place. The diamonds, of course, carry out the cutting. As the blade operates, the bond wears away; hence, diamond grit is shed, and fresh, sharp diamonds are uncovered.
How hard the blade’s bond affects the blade’s durability and how fast it sheds worn diamond grit. As a rule, blades with softer bonds cut better than hard-bonded blades on hard and dense materials. This is because soft-bonded blades wear more quickly, therefore they are able to uncover fresh diamond grit faster. The result is an overall better cutting performance when it comes to hard materials.
But for soft materials, soft-bonded blades are not a good choice as they simply get used up faster in such operation. When it comes to undercutting especially, the more you shouldn’t pick up a blade with a soft bond as it may cause segment loss during operation.
Hard-bonded blades, on the other hand, operate better on soft, porous materials, as opposed to soft-bonded blades. Hard-bonded blades are more durable and they last longer. This is because they are capable of enduring the abrasiveness of soft materials.
By and large, you must use a soft-bonded blade to operate on hard, dense materials and a hard-bonded blade to operate on soft, porous materials. If all these still confuse you, consulting the manufacturer by phone or asking the dealer personally will help you get through. There is also such a thing as a medium/soft-bonded blade, which a store personnel should recommend if you are looking for a multi-purpose blade.
Choosing between a hard-bonded blade and a soft-bonded blade shouldn’t be a problem at all. Having some knowledge about the tool and not having the diffidence to inquire is what it all comes down to.