Why the Right Grinder Makes or Breaks the Job
Concrete grinding is not one-size-fits-all. The wrong machine means slow material removal, premature tooling wear, and poor surface finish. Whether you're prepping a garage slab, removing coatings, or flattening a warehouse floor, matching the grinder to the job is the first decision to get right.
Single-Head vs Planetary: Understanding the Difference
Single-head grinders use one large grinding disc or cup wheel. They're simpler, lighter, and easier to maneuver in tight spaces — ideal for edge work, small areas, and jobs where portability matters.
Planetary grinders use multiple smaller satellite heads that rotate on their own axes while the main plate also rotates. This produces a more consistent scratch pattern, better surface contact on uneven slabs, and significantly higher production rates. They're the standard for commercial and industrial floor prep.
The Full Lineup: G1 to G7
Grand Diamond Tools carries seven machines covering everything from residential spot work to large-scale industrial grinding.
| Model | Name | Motor | Working Width | Weight | Phase |
|---|---|---|---|---|---|
| G1 | MI-G1 | — | — | — | Single |
| G3 | MI-G3 | — | — | — | Single |
| G4 | MI-Kangaroo | 4 kW / 20A | 19 in (483 mm) | 445 lbs / 202 kg | Single |
| G4.5 | MI-Badger | 4 kW / 20A | 21 in | 445 lbs / 202 kg | Single |
| G5 | MI-Lion | 5.5 kW / 20A | 22 in (558 mm) | 490 lbs / 222 kg | Single |
| G6 | MI-Tiger | 11 kW / 36A | 26 in (660 mm) | 795 lbs / 361 kg | Three |
| G7 | MI-Elephant | 15 kW (20 HP) / 36A | 32 in (812 mm) | 1,102 lbs / 500 kg | Three |
All models run 220V (60Hz) except the G7 which requires 460V three-phase. Pricing is subject to change and is current as of August 26, 2026.
Machine-by-Machine Breakdown
G1 MI-G1
The compact entry-level machine in the lineup. Best suited for residential slab prep, small areas, and jobs where portability and ease of transport are the priority. Ideal for contractors who need a capable machine without the footprint of a larger planetary grinder.
G3 MI-G3
The three-head planetary step-up from the G1. Delivers a more consistent scratch pattern and higher production rate than a single-head machine, while remaining manageable for commercial floor prep. A strong all-around choice for open floor areas.
G4 MI-Kangaroo — $7,800
The entry point into the larger planetary lineup. At 19 inches wide and 445 lbs, the Kangaroo delivers serious production capability on a single-phase 220V circuit — no special electrical required. A strong choice for contractors stepping up from smaller machines or working on residential and light commercial jobs.
G4.5 MI-Badger — $7,800
Same motor and price as the Kangaroo but with a wider 21-inch working path. If you're running the same electrical setup and want more coverage per pass, the Badger is the better value. Ideal for open floor areas where the extra width pays off in time saved.
G5 MI-Lion — $12,000
The Lion steps up to a 5.5 kW Siemens motor and a 22-inch working area at 490 lbs. Still single-phase, making it accessible without a three-phase electrical upgrade. The power increase over the G4/G4.5 is meaningful on harder concrete and heavier coating removal. A well-rounded production machine for commercial floor prep.
G6 MI-Tiger — $28,600
The Tiger crosses into heavy industrial territory. At 11 kW, 26 inches wide, and 795 lbs, it requires a three-phase 220V supply but delivers the output to match. Built for high-production commercial and industrial jobs — warehouses, distribution centres, large retail slabs.
G7 MI-Elephant — $36,400
The flagship. 32-inch working width, 15 kW (20 HP) Siemens motor, 1,102 lbs, and 460V three-phase power. The Elephant is purpose-built for maximum productivity on large industrial floors. If you're grinding tens of thousands of square feet, this is the machine that makes the economics work.
Matching the Machine to the Job
| Job Type | Recommended Model | Reason |
|---|---|---|
| Garage / residential slab | G1 MI-G1 | Compact, easy to transport |
| General commercial prep | G3 MI-G3 | Planetary consistency, manageable size |
| Light commercial / step-up | G4 MI-Kangaroo | Single-phase, wider coverage |
| Open commercial floors | G4.5 MI-Badger | Extra width at same price as Kangaroo |
| Hard concrete / heavy coatings | G5 MI-Lion | More power, still single-phase |
| Warehouse / industrial | G6 MI-Tiger | High output, three-phase |
| Large-scale industrial | G7 MI-Elephant | Maximum width and power |
Electrical Requirements: Plan Before You Buy
The G4, G4.5, and G5 all run on single-phase 220V — standard on most job sites and shops. The G6 requires three-phase 220V and the G7 requires 460V three-phase. If your site doesn't have three-phase, factor in the cost of an electrical upgrade or a phase converter before committing to the larger machines.
Don’t Forget Tooling Compatibility
Every machine in this lineup is only as good as the segments running under it. Confirm tooling system compatibility — Redi-Lock, SASE, Diamatic/Dialoc, HTC, or proprietary — before purchasing. Grand Diamond Tools stocks segments for all major systems and can help you match bond hardness and grit to your concrete hardness and target CSP.