In the world of professional concrete floor grinding, the diamond tool is only as good as the bond that holds it. Using the wrong bond is the fastest way to lose money—either through premature tool wear or by "glazing" the diamonds, which halts productivity.
To maximize efficiency and lifespan, you must match the metal bond hardness to the concrete hardness. Here is the technical breakdown of how to make the right choice.
1. Understanding the "Opposites Attract" Rule
The fundamental principle of diamond grinding is: Opposites Attract.
Hard Concrete requires a Soft Bond.
Soft Concrete requires a Hard Bond.
Why? A soft bond wears away faster, constantly exposing new, sharp diamonds to cut through dense, hard concrete. Conversely, a hard bond resists the abrasive nature of soft concrete, preventing the tool from disappearing in minutes.
2. Testing Concrete Hardness (The Mohs Scale)
Before selecting your grinding segments, you must know what you are cutting. We recommend using a Mohs Hardness Scratch Test Kit.
Mohs Scale Result | Concrete Classification | Recommended Bond |
2 – 3 | Very Soft (Abrasive, rain-damaged) | Extra Hard Bond |
3 – 5 | Soft / Medium | Hard / Medium Bond |
5 – 7 | Hard (Standard high-psi mix) | Soft Bond |
7 – 9 | Very Hard (Quartz-heavy, power-troweled) | Extra Soft Bond |
3. Key Factors in Bond Selection
When browsing a professional catalog (like the Likn Superabrasive series), consider these four technical attributes:
Processing Technology: For extremely hard concrete, Vacuum Brazed tools or specialized Sintered segments with high cobalt content offer the best "open" structure for cutting.
Material Matrix: The metal powder (bond) and the diamond grit size must work in harmony. Coarser grit (16/20#) is ideal for soft, abrasive concrete to remove material quickly.
Application Environment: Wet grinding cools the bond and speeds up the cutting process, allowing for slightly harder bonds. Dry grinding generates more heat, requiring a bond that can handle thermal stress without glazing.
4. Signs You’ve Made the Wrong Choice
Keep an eye on your machine’s performance. The floor will tell you if the bond is mismatched:
The "Glazing" Effect (Bond too hard): The segment feels smooth to the touch, looks shiny, and stops cutting. You are essentially "polishing" the concrete instead of grinding it.
Solution: Switch to a Softer Bond or use an abrasive (like sand) to re-open the diamonds.
The "Melting" Effect (Bond too soft): The segments are wearing down at an alarming rate (e.g., losing 2mm in 100 square feet).
Solution: Switch to a Harder Bond immediately to protect your investment.
5. Conclusion
Choosing the right bond is a balance of science and on-site experience. By identifying the concrete hardness first and selecting a professional-grade tool—such as the PHX series or Husqvarna-compatible segments—you ensure the lowest cost per square foot and the highest quality finish.
Pro Tip: Always keep a set of "Soft" and "Hard" bonds in your van. Concrete hardness can change from one end of a warehouse to the other!
