Choosing the right diamond tooling is one of the most important parts of getting a good result when grinding concrete. The grinder itself does the work, but the diamonds determine how aggressively the machine cuts, how smooth the floor finishes, and how well the machine handles different types of concrete.
At Peninsula Products, each grinder hire comes with a specific set of diamond tooling suited to that machine. This guide explains the diamonds supplied with each grinder and when each option is generally used
Understanding diamond grits and bonds
Grit
The grit number refers to how aggressive or fine the diamond is.
Lower grit diamonds are more aggressive and are used for heavy cutting, coating removal, glue removal, surface preparation, or opening up the concrete.
Higher grit diamonds are finer and are used to refine the floor after the initial grind.
As a general guide:
30 grit is used for aggressive grinding and surface preparation.
60/80 grit is used for a finer finishing pass, often before sealing.
16 grit or 25 grit arrow tooling is more aggressive and is generally used where extra cutting power is needed, such as glue, coatings, high spots, or rough concrete.
Bond
The bond refers to how hard or soft the metal is that holds the diamond.
Hard bond diamonds are generally used on softer concrete.
Soft bond diamonds are generally used on harder concrete.
Medium bond diamonds are a good all-round option and are commonly used for general grinding or finishing passes.
Getting the bond right matters. If the wrong bond is used, the diamonds may wear too quickly or may not expose fresh diamond properly, which can reduce grinding performance.
Diamond selection provided with each grinder from Peninsula Products
Small grinder: 280mm concrete grinder
Our small 280mm grinder is suited to smaller areas, edges, tight spaces, and lighter grinding work. It is a practical option for small DIY jobs or areas where a larger machine is difficult to use.
Diamonds supplied with the 280mm grinder
| Type | Bond | Grit | Style | Quantity |
|---|---|---|---|---|
| Redi Lock | Hard | 30 | Coffin | 6 |
| Redi Lock | Soft | 30 | Coffin | 6 |
| Redi Lock | Medium | 60/80 | Coffin | 6 |
How to use these diamonds
For the first cut, you would generally choose either the hard 30 grit or soft 30 grit diamonds depending on the hardness of the concrete.
Use the 30 grit diamonds when you need to remove surface contamination, open up the slab, remove minor coatings, or prepare the floor for sealing.
Once the initial grind is complete, the medium 60/80 grit diamonds can be used to refine the floor and leave a more even surface before sealing.
The 280mm grinder is not designed to be the fastest option for large open areas, but it is useful where access, size, or control is important.
Medium grinder: 480mm concrete grinder
Our 480mm grinder is one of the most popular options for DIY concrete grinding and garage grind-and-seal projects. It is large enough to be productive, while still being manageable for many residential and light commercial jobs.
Diamonds supplied with the 480mm grinder
| Type | Bond | Grit | Style | Quantity |
|---|---|---|---|---|
| Plugs | Hard | 30 | Coffin | 3 |
| Plugs | Soft | 30 | Coffin | 3 |
| Plugs | Soft | 16 | Arrows | 3 |
| Discs | Medium | 30 | Coffin | 3 |
| Discs | Medium | 60/80 | Coffin | 3 |
How to use these diamonds
The 480mm grinder comes with a broader range of tooling because it is commonly used for different types of floor preparation.
The 16 grit soft arrow diamonds are the most aggressive option supplied with this grinder. These are generally used when the floor needs heavier cutting, such as glue removal, coating removal, rough concrete, or high spots.
The 30 grit coffin diamonds are used for general grinding and floor preparation. Depending on the slab, you may use the hard bond or soft bond option to suit the concrete hardness.
The medium 30 grit discs are a good general grinding option, while the medium 60/80 grit discs are used as a finer finishing pass before sealing.
For many grind-and-seal jobs, the process will usually involve starting with an aggressive cut, then refining the floor with 60/80 grit diamonds before vacuuming and applying sealer.
Large grinder: 680mm concrete grinder
Our 680mm grinder is suited to larger areas where productivity matters. This machine is better suited to open spaces, larger sheds, commercial floors, and bigger concrete preparation jobs.
Diamonds supplied with the 680mm grinder
| Type | Bond | Grit | Style | Quantity |
|---|---|---|---|---|
| Redi Lock | Hard | 30 | Coffin | 9 |
| Redi Lock | Soft | 30 | Coffin | 9 |
| Redi Lock | Soft | 25 | Arrows | 9 |
| Redi Lock | Medium | 30 | Coffin | 9 |
| Redi Lock | Medium | 60/80 | Coffin | 9 |
How to use these diamonds
The 680mm grinder is supplied with enough tooling to suit larger floor areas and more demanding grinding work.
The 25 grit soft arrow diamonds are the most aggressive option supplied with this machine. These are generally used where the floor needs stronger cutting action, such as coatings, glue, heavy surface contamination, uneven concrete, or a rough first pass.
The 30 grit coffin diamonds are used for general grinding and surface preparation. The hard, soft, and medium bond options allow the tooling to be matched to the concrete.
The medium 60/80 grit coffin diamonds are used for the finer finishing pass. This is commonly done before sealing to help create a more consistent finish.
The 680mm grinder is a strong option when the project is too large for a 480mm grinder but does not require the biggest machine in the fleet.
Large RC grinder: 830mm concrete grinder
Our 830mm grinder is the largest grinder in this guide and is suited to serious floor preparation work. It is designed for large areas where production speed, consistency, and grinding power are important.
Diamonds supplied with the 830mm grinder
| Type | Bond | Grit | Style | Quantity |
|---|---|---|---|---|
| Redi Lock | Hard | 30 | Coffin | 18 |
| Redi Lock | Soft | 30 | Coffin | 18 |
| Redi Lock | Soft | 25 | Arrows | 18 |
| Redi Lock | Medium | 30 | Coffin | 18 |
| Redi Lock | Medium | 60/80 | Coffin | 18 |
How to use these diamonds
The 830mm grinder is supplied with the same general diamond range as the 680mm grinder, but in a larger quantity to suit the bigger grinding head.
The 25 grit soft arrow diamonds are used when the floor needs a more aggressive first cut. This may include coating removal, glue removal, heavy preparation, or cutting through rough concrete.
The 30 grit coffin diamonds are used for general grinding and surface preparation. With hard, soft, and medium bond options supplied, the tooling can be matched to suit the slab.
The medium 60/80 grit diamonds are used for refining the floor after the first grind. This helps produce a cleaner and more consistent surface before sealing.
The 830mm grinder is best suited to large open areas where speed and efficiency are important.
Which diamonds to start with?
For most concrete grinding projects, the starting point depends on the condition of the floor.
If the floor is clean and only needs basic preparation, a 30 grit coffin diamond is usually the best starting point.
If the floor has glue, coatings, rough patches, or needs heavier cutting, the arrow diamonds are the more aggressive option.
If the floor has already been opened up and you are preparing to seal, the 60/80 grit diamonds are used to refine the surface.
As a simple guide:
Use arrow diamonds for heavy cutting.
Use 30 grit coffin diamonds for general grinding.
Use 60/80 grit diamonds for the finishing pass before sealing.
Use hard bond diamonds on softer concrete.
Use soft bond diamonds on harder concrete.
Use medium bond diamonds for general-purpose grinding and refining.
Need help choosing the right grinder or diamonds?
Every hire comes with the diamonds suited to that grinder, and our team can help guide you on which option to start with based on your project.
When we deliver the equipment, our driver can help set up the machine, explain the tooling, and give practical advice based on the condition of your concrete. This helps make sure you are starting with the right diamonds and getting the best result from the machine.
Whether you are grinding a small area, a garage floor, a shed slab, or a larger commercial space, choosing the right grinder and diamond tooling will make the job faster, easier, and more consistent.