How to choose the right grinding segment for your concrete floor

Technical Guide · Floor Grinding

Professional education

How to choose the right grinding segment for your concrete floor

Two factors determine your result. Get them wrong and you’ll burn through segments — or stall on the floor entirely.

Whether you’re removing coatings, leveling a slab, or preparing a surface for polishing — the grinding segment you choose defines everything: how fast you work, how long your tooling lasts, and the quality of the end result.

There are exactly two selection factors that matter. Most contractors focus on the first. The professionals who optimize both are the ones who never waste a segment.

Grit size

Controls how aggressive the grinding action is. Low grit cuts hard and fast. High grit refines the surface.

Bond hardness

Controls how the segment behaves on the floor. Determined by concrete strength — often overlooked, always important.

Factor 1

Grit size: how aggressive is the cut?

Grit refers to the size of the diamond particles embedded in the segment. The lower the grit number, the larger and more aggressive the diamonds — and the more material removed per pass. Higher grit means finer, more controlled contact with the surface.

Grit	Category	Typical application
#16 / #20 / #25 / #30	Coarse	Coating removal, bitumen stripping, aggressive stock removal
#60 / #80 / #100	Medium	Surface leveling, scratch removal, general preparation
#120 / #150	Fine	Final surface preparation before polishing
#150+	Polishing	Resin polishing pads recommended — metal shoes less effective at this range

Practical note

For grinding above #150 grit, switch to resin polishing pads. Metal grinding shoes are optimized for the coarse-to-medium range — beyond that, resin delivers better results and longer tool life.

Factor 2

Bond hardness: matching the tool to the floor

The bond is the metal matrix that holds the diamond particles in place. As the segment grinds, the bond wears away — exposing fresh diamonds. The rate at which this happens must match the hardness of the floor you’re working on.

This is the counterintuitive rule that trips up many contractors:

Hard floor

↓

Use a soft bond — the hard floor won’t naturally wear the segment, so a softer bond self-opens to expose fresh diamonds

Medium floor

↔

Use a medium bond — balanced wear rate for standard industrial concrete

Soft floor

↑

Use a hard bond — soft concrete wears segments quickly, so a harder bond extends tool life

The golden rule

Hard concrete → Soft bond. Soft concrete → Hard bond. Mismatching bond to floor is the single most common cause of premature segment wear and poor grinding performance.

Concrete classification

Reading the floor: C-class and bond selection

Concrete strength is expressed in C-classes (compressive strength). In practice, most contractors gauge floor hardness from experience, grinding behavior, and segment wear — rather than laboratory tests. The table below maps floor type to the correct bond.

Floor type	Code	Concrete class	Mohs	Recommended bond
Very soft floor	VSF	C25 or less	—	Hard bond
Soft floor	SF	C25	2–4	Hard bond
Medium floor	MF	C25–C30	3–4	Medium bond
Hard floor	HF	C30–C35	4–6	Soft bond
Very hard floor	VHF	C35–C40	5–6	Soft bond

Mohs hardness (a 1–10 mineral scale) gives an additional reference point. Concrete typically falls between Mohs 3–6. While useful context, it is rarely measured on-site — experienced contractors read the floor by how it responds to the machine.

Practical examples

What does this look like in the field?

Bitumen removal — hard industrial slab

Floor typeHard floor (HF)

Concrete classC30–C35

Recommended grit#20 / #30

Recommended bondSoft bond

Surface leveling — softer slab

Floor typeSoft floor (SF)

Concrete classC25

Recommended grit#60

Recommended bondHard bond

Summary

Putting it together

For most everyday jobs, grit size is the primary decision — it determines the application. Bond hardness is the optimization layer: it separates good results from great results, and prevents costly segment wear on demanding projects.

Price lists and product catalogues typically highlight grit and application type. But behind every professional recommendation is a bond selection matched to the floor — and that’s where the real performance difference lies.

BYCON Europe · Technical Advice

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