A diamond blade is the single most important consumable on a concrete cutting job. Choose wrong and you burn through segments in 50 linear feet, overheat the steel core, or leave a ragged edge that costs you time on cleanup. Choose right and the blade practically feeds itself through the material. This guide covers the variables that matter — bond hardness, segment type, arbor compatibility, and wet vs dry operation — so you can match the blade to the job every time.
Understanding Bond Hardness
The bond is the metal matrix that holds the industrial diamonds in each segment. Bond hardness is relative to the material you are cutting — not an absolute measure of blade quality.
- Soft bond — Use on hard, dense materials like cured reinforced concrete (4,000+ PSI), granite, and hard aggregate. The softer matrix wears away faster, continuously exposing fresh diamonds so they can bite into the hard surface.
- Medium bond — General-purpose choice for block, brick, medium-cure concrete, and pavers. Suitable when you are cutting a mix of materials throughout the day.
- Hard bond — Use on abrasive, soft materials like green (uncured) concrete, asphalt, sandstone, and limestone. The harder matrix resists premature wear from abrasive grit that would strip a soft bond bare.
The most common mistake in the field: running a hard-bond blade on cured concrete. The diamonds glaze over because the bond will not release them — the blade stops cutting and overheats. If you see the blade skating across the surface instead of sinking in, bond hardness is almost always the issue.
Segment Types and Configurations
Segments are the diamond-bearing teeth around the blade perimeter. Three configurations cover 90% of jobsite needs:
Segmented (Gulletted)
Gaps between segments allow air cooling and slurry removal. Best for dry cutting and general concrete work. Most common configuration for walk-behind flat saws and hand-held cut-off saws.
Continuous Rim
Unbroken diamond edge. Produces the cleanest cut with minimal chipping. Required for tile, porcelain, and decorative stone. Always used wet — no air gaps means no air cooling.
Turbo
Serrated continuous rim — compromise between speed and finish quality. Good for masonry, concrete, and stone when you need a cleaner cut than segmented but faster production than continuous rim.
Segment height determines blade life. A 10mm segment lasts roughly twice as long as a 7mm segment on the same material. For production cutting — highway joints, utility trenches, demolition — choose the tallest segment your equipment can handle. For finish work and occasional use, standard height segments are more economical.
Wet Cutting vs Dry Cutting
Water does three things: cools the blade, flushes abrasive slurry out of the cut, and suppresses silica dust.
- Wet cutting extends blade life 3–5× over dry cutting on the same material. Mandatory for continuous-rim blades, core bits, and any cut deeper than 4 inches. Required on most flat-saw and wall-saw operations.
- Dry cutting is acceptable for short, shallow cuts with segmented blades — control joints in a basement slab, cutting CMU block, small openings. Let the blade cool every 30–60 seconds. Never force a dry blade — if it is not cutting, you are glazing the segments.
OSHA Silica Rule (Table 1): For handheld cut-off saws on concrete/masonry, the specified exposure control method is an integrated water delivery system that supplies a continuous stream to the blade. Dry cutting without engineering controls requires air monitoring and often a respirator program.
Matching Blade Diameter and Arbor Size
Common blade diameters and their typical applications:
| Diameter | Typical Equipment | Common Arbor |
|---|---|---|
| 4"–5" | Angle grinder, tuckpointing saw | 7/8" or 5/8" |
| 7"–9" | Circular saw, small cut-off saw | 5/8", ⅞", or 20mm |
| 12"–14" | Gas/electric cut-off saw (Husqvarna K770, Stihl TS 800) | 1" or 20mm |
| 18"–24" | Walk-behind flat saw | 1" |
| 26"–72" | Self-propelled flat saw, wall saw | 1" pin-drive |
Always verify the arbor size before ordering. A blade with a 1" arbor will not fit a machine with a 20mm spindle without a bushing — and bushings introduce wobble that shortens blade life and degrades cut quality.
Rules of Thumb for the Field
- Let the blade do the work. Downward pressure should be just enough to keep the blade engaged — if you are leaning on the machine, the blade is wrong for the material.
- Check RPM ratings. A 14" blade rated for 4,400 RPM on a saw spinning at 5,500 RPM is a safety hazard. Always match or exceed the machine RPM rating.
- If the blade undercuts (pulls to one side), the diamond segments are wearing unevenly. Make a few cuts in abrasive material (asphalt, green concrete) to re-round the segments.
- Replace blades before the segments wear down to the steel core. Running on the core damages the blade body and risks the segment detaching at speed.
- Store blades flat or hung by the arbor hole. Stacking blades on edge can warp the steel core on thinner blades.
What We Stock
ConcreteProDirect carries diamond blades from Husqvarna, Diamond Products, MK Diamond, and ICS — from 4" grinder blades to 72" flat-saw blades. Every blade page on our site lists bond type, segment height, recommended material, and RPM rating. If you are not sure which blade fits your saw or your application, call us — we cut concrete too, and we will point you to the right product.