Quick Answer

Three decisions make up segment selection: the bond (matched to concrete hardness), the grit (matched to the stage of the job) and the segment style (matched to the machine and the type of grinding). Get the bond wrong and the tool either glazes or wears out in hours.

For machine-matched tooling, browse our 3'' Metal Bond Diamond Grinding Disc with 4 Segments range.

Step 1: Match the Bond to the Concrete

• Soft bond: for hard, dense concrete with granite or quartz aggregate - it exposes diamonds fast enough to cut
• Medium bond: for standard concrete with gravel or river stone - the everyday default
• Hard bond: for soft, sandy concrete - holds diamonds longer so they are not knocked out too soon

Step 2: Choose the Grit by Job Stage

• 6#-16#: levelling, heavy stock removal, coating breakdown
• 30/40#-60/80#: smoothing, scratch refinement
• 100/120#-200#: fine honing before resin work

Step 3: Pick the Segment Style

Segment shape affects aggressiveness and surface contact. Round segments give smooth, steady grinding on floors; bar segments are versatile and common; arrow and zigzag segments cut more aggressively on harder materials. Trapezoid plates suit universal trap-style holders, while round plates suit Redi-Lock and similar quick-change systems.

Machine Compatibility

Check your grinder's holder system before buying: trap-style plates, Redi-Lock, magnetic or bolt-on. The same diamond segment is often available in different plate styles, so always order the version that matches your machine brand.

Frequently Asked Questions

Q: How do I test concrete hardness?

A>Use a hardness tester, or do a simple scratch test with a nail or the plate itself on a test area.

Q: What if the concrete varies across the floor?

A>Use the bond matched to the majority of the floor, and adjust machine speed and pressure where needed.

Q: Can I use the same segment for epoxy removal?

A>For coatings, use PCD tools first; metal bond segments are better on bare concrete.

Q: How do I know the segment is worn out?

A>When the segment height drops significantly, the plate loses speed, or diamonds are no longer exposed and the tool glazes.

Looking for the right tool? Check our 3'' Metal Bond Diamond Grinding Disc with 10 Segments. Looking for the right tool? Check our 3'' Metal Bond Diamond Grinding Disc with 5 Segments.

Conclusion

Bond, grit and segment style work together. Match all three to the concrete and the stage of the job, and your grinding passes become faster and cheaper per square metre.