Quick Answer

Three grinding head types cover most concrete work: PCD (polycrystalline diamond) heads strip coatings, paint, and adhesives fast; tungsten carbide heads level concrete, grind glue, and handle soft concrete; diamond metal-bond heads grind concrete itself with a smooth finish. Use PCD for removal, tungsten for shaping and soft surfaces, and diamond for final concrete grinding. On a diamond trapezoid grinding disc, metal-bond segments give the longest life on hard cured concrete.

PCD Grinding Heads

PCD heads use flat polycrystalline diamond plates brazed to the segment, cutting like a scraper rather than a grinder. They excel at removing paint, epoxy, mastics, and thin coatings from concrete without digging into the slab, and they work well on soft concrete. PCD heads cut fast but wear quickly on hard, abrasive concrete and cannot produce a smooth finish; they are a removal tool. Use PCD first to strip the coating, then switch to metal bond to refine the surface.

Tungsten Carbide Heads

Tungsten carbide heads have sharp carbide teeth that shave the concrete surface. They are the best choice for levelling high spots, removing glue and mastics, and grinding soft or green concrete, where diamond segments would glaze over. Tungsten heads cut aggressively and leave a coarse finish, so follow with metal bond for a smooth surface. They wear quickly on hard concrete and are not economical for large hard-slab jobs, but they are the go-to for adhesive removal and levelling work.

Diamond Metal-Bond Heads

Diamond metal-bond heads are the workhorse for grinding concrete itself. Diamonds are embedded in a metal matrix that wears to expose fresh diamond, so they grind hard cured concrete efficiently and last far longer than PCD or tungsten on abrasive slabs. Choose the bond to match the concrete: soft concrete needs a hard bond, hard concrete needs a soft bond, so the matrix wears at the right rate. Metal-bond heads come in several grits; coarse (30-40 grit) for removal, fine (80-200 grit) for smoothing and prep for polishing.

Choosing by Job Type

For a painted garage floor, use PCD to strip the paint, then a coarse metal bond to blend the surface. For glue or mastic removal, tungsten carbide is fastest, followed by metal bond. For levelling a bumpy slab, tungsten or coarse metal bond, checking with a straightedge. For preparing concrete for coating or polishing, work through coarse to fine metal bond. Match the head to the machine size: 125 mm discs for angle grinders, and larger heads or plates for walk-behind floor machines.

Wear, Life, and Costs

Head life varies with concrete hardness, pressure, and how much you are removing. PCD may last one floor on soft concrete and a fraction on hard; tungsten similar; metal bond lasts the longest on concrete but wears fastest on coatings. Compare cost per square metre, not sticker price: a cheaper head that wears out mid-floor costs more in downtime and disc swaps. Keep a spare of the head you use most, and rotate or flip heads where the design allows for even wear.

For dependable concrete grinding, equip your machine with a diamond trapezoid grinding disc matched to the concrete hardness.

See the diamond grinding cup wheels to keep every stage of the job running with quality consumables.