Bond Hardness Selection for Concrete vs Granite Diamond Blades

A practical buyer guide to matching diamond blade bond hardness with concrete versus granite so cutting speed and segment life stay in balance.

Bond hardness is one of the first specifications importers should lock before ordering OEM diamond blades. The metal matrix that holds the diamond grit must wear at a rate that matches the workpiece: too hard and the blade glazes; too soft and the segments disappear before the job is finished. Protec Tools reviews bond choice with buyers against material hardness, abrasive content and whether the cut is wet or dry.

Why concrete and granite need different bonds

Cured concrete is often more abrasive than it looks, especially when it contains hard river sand or granite aggregate. A relatively soft bond lets worn diamonds shed so fresh grit is exposed. Dense granite and other natural stone tend to polish a soft bond, so a harder matrix is used to keep diamonds standing until they actually fracture the stone.

Soft to medium-soft bonds: general-purpose concrete, asphalt overlay and heavily sanded slabs.
Medium bonds: reinforced concrete with mixed aggregate and some granite curbstone work.
Hard bonds: hard granite, engineered quartz and low-abrasion porcelain on a dedicated stone blade.
Never assume one bond covers both a demolition crew and a stone fab shop.

What to put on the purchase order

Ask the factory to name the intended material, wet/dry use and machine type on the drawing. If your distributors sell both construction and stone blades, keep SKUs separate rather than stretching one bond across two markets. Sample cuts on the customer actual slab remain the fastest way to confirm the matrix before a container is packed.

For OEM programs, send a short material list with each RFQ and request a recommended bond code. That paperwork also helps after-sales teams explain wear patterns if a blade is later used on the wrong substrate.