3. Key Selection Parameters
3.1 Diamond Grit Size
Diamond grit size is measured in mesh (e.g., 30/35, 40/50, 50/60, 60/80). The selection rule is:
Harder materials: Finer grit is preferred. Under equal pressure, finer diamonds are sharper and penetrate hard materials more effectively .
Softer materials: Coarser grit cuts faster and is more aggressive.
Larger diameter blades: Coarser grit (e.g., 30/40, 40/50) for higher cutting efficiency .
Smaller diameter blades: Finer grit (e.g., 50/60, 60/80) for smoother cut surfaces .
3.2 Diamond Concentration
Concentration refers to the density of diamonds in the working layer. Standard concentration is defined as 100% when the segment contains 4.4 carats of diamond per cubic centimeter of bond material .
Higher concentration increases blade life because each diamond carries less cutting load. However, higher concentration also increases cost. The optimal concentration depends on:
Material hardness and abrasiveness
Required cutting speed
Economic considerations (cost per cut)
Generally, higher bond hardness requires higher diamond concentration to maintain cutting efficiency .
3.3 Segment Design
Different segment geometries serve different cutting applications :
|
Segment Type |
Best Application |
Characteristics |
|
Segmented |
Demolition, road work, dry cutting |
Gaps between segments provide cooling and debris removal; fast cutting |
|
Continuous rim |
Tile, porcelain, natural stone |
Chip-free finish; requires wet cutting; slower speed |
|
Turbo |
Mixed materials, outdoor paving |
Combines speed and finish quality; reduces downtime by up to 40% versus mismatched blades |
4. Material-Specific Selection Guidelines
4.1 Concrete: A Three-Category Material
Concrete is not a single material-three distinct states require different blade specifications :
Cured Concrete: Hard and dense but not highly abrasive. Requires soft to medium bond. This is the primary use case for flat sawing and handheld cutting of hardened slabs, foundations, and structures .
Green (Fresh) Concrete: The cement paste has not fully bonded the aggregate; sand acts as loose abrasive that quickly wears soft bonds. Requires hard bond, typically with early-entry geometry and flange protection .
Reinforced Concrete: Intermittent steel contact impacts the segment tips. Requires medium bond with tougher diamond grades and segment designs that resist steel impact without losing diamonds .
4.2 Granite and Natural Stone
Granite is hard and dense-requiring a soft bond to maintain sharpness. The bond must wear fast enough to expose new diamonds as they dull against the hard rock .
Quartzite deserves separate consideration. With a Mohs hardness near 7 (pure quartz), it is both hard and highly abrasive-more demanding than most granite. High-end stone processing treats quartzite as a distinct category .
4.3 Marble
Marble is characterized by high brittleness and susceptibility to cracking. It requires:
Finer diamond grit to minimize impact and vibration
Stable cutting conditions to prevent edge chipping
Careful feed rate control
Coarse grit or overly aggressive bond exposure can cause micro-cracks and edge chipping that cannot be polished out .
4.4 Tile and Porcelain
Tile and porcelain are dense and low-toughness, making them prone to chipping, especially at the glaze layer. Requirements include:
Continuous rim blades for chip-free cuts
Fine diamond grit
Stable, consistent feed rate without wobble
4.5 Asphalt
Asphalt is abrasive rather than hard. The loose aggregate particles wear the metal bond, so a hard bond is required to resist this erosion .
