Grinding segments: choose the bond opposite to the concrete

The explanation is that the bond should wear away in step with the diamonds. If it wears too slowly, the worn diamonds stay in place and the segment glazes instead of cutting. If it wears too quickly, fresh diamonds are shed before they have done their job.

Six hardnesses, six colours

The Husqvarna Redi Lock range is graded on a six-step scale. The colour is the code — it is on the segment, so you can see what is fitted to the machine today:

• G1110 black — bond: soft 1, for very hard concrete. Can also be used for dry grinding of natural stone (calcareous) and terrazzo
• G1120 yellow — soft 2, for very hard concrete
• G1140 pink — medium 1, for medium to hard concrete
• G1150 grey — medium 2, for soft to medium-hard concrete
• G1170 red — hard 1, for soft concrete and porous surfaces, for example concrete with a brushed finish and grout for ceramic tiles
• G1180 blue — hard 2, for soft concrete and porous surfaces

Grit size is a separate choice

The bond is chosen to suit the concrete. The grit size is chosen according to where you are in the job: coarse grit removes material, fine grit finishes the surface.

Black, yellow, pink and grey are supplied in grits 20, 30, 60 and 120. Red and blue are only supplied in 20 and 30 — they are intended for coarse work on soft surfaces. When polishing, the surface treatment is carried out in three steps before moving on to resin-bonded tools.

Single, double or triple

The segments are available as single or double H segments, and for the four softest bonds also as a convex segment. Blue G1180 is also available as a triple segment: longer service life and higher speed, intended for very abrasive surfaces.

More segments per unit means more diamond against the floor, but also that the grinding pressure is spread over a larger area. That is why the choice depends on which machine you have — see the guide to choosing a floor grinder for that side of the equation.

Piranha for coatings and adhesive

If you are not grinding concrete but removing something on top of it, Piranha is the answer: PCD scrapers for PG machines, in the same Redi Lock fitting. They remove coatings, adhesive and deposits that are otherwise hard to get off.

The design is a single or double quarter-round PCD disc with a protective diamond strip, and the tool can be fitted with a new tip when the old one is worn out.

The holder plate and the fitting

Redi Lock is a quick-change fitting: the segments are changed without screws, and you don't need several sets of holder plates for different diamond tools. The system is available for a range of machine makes, not just Husqvarna's own.

The holder plate in the catalogue is Tool Holder Redi Lock® 270 6 H measuring 270 × 270 × 10 mm, part number 502 53 22-01.

Dry or wet

Husqvarna recommends using the Redi Lock segments dry. This extends the tool's service life and saves time, since no time is spent mopping up slurry afterwards. Wet grinding is still possible.

When you order

State which machine the segments are for, which colour is fitted today, and whether it is coarse work or finishing. If you don't know how hard the concrete is, the general rule in the user manual for the PG 680 and PG 820 is to start with a harder bond: it causes the least wear on the diamonds, and if it is not right, it has only cost a little time.