Concrete grinding discs are crucial to a mason or handyman who often cuts or grinds concrete materials. If this happens to be your profession, then a grinding disc is one tool you might not be able to do without. Firstly, Grinding discs are abrasive grinding/cutting tools as you will find bits of abrasive grains on the surface of grinding discs. They constitute a large part of the grinding disc. Without these grits, you may as well not have a grinding disc. We’ll explore tips when selecting the right concrete grinding disc for angle grinders.
What are the tips to consider when selecting concrete grinding discs?
Table of Contents
- 1. Always check the expiry date of your concrete grinding disc.
- 2. Buy cheap, buy twice.
- 3. Bond strength and wheel structure
- 4. Size and grinding discs
- 5. The grit of the concrete grinding disc
- 6. Consider the abrasive.
- Final thoughts
Fig. 1 – A handyman using an angle-grinder
1. Always check the expiry date of your concrete grinding disc.
So, grinding discs come with expiry dates? Yes, they do. Don’t feel left out; a handful of people don’t know this. Expiry dates appear in month and year format on grinding discs. Manufacturers imprint these expiry dates on grinding discs as they should comply with the manufacturing regulation. You will likely find this date on the center ring of this disc. Plus, the expiry date is usually three years from the manufacture date. On smaller discs, you might find the expiry date on the label or probably the disc itself. Why do concrete grinding discs come with expiry dates?
Well, if you wish to find out, read on. The reason these discs come with expiry dates is due to the resin the manufacturer makes use of in the manufacturing process. The resin plays a vital role in the grinding disc as it helps to bond the abrasive. Over time, the wax starts to absorb moisture, leading to the grinding disc deterioration. Using a grinding disc after its expiry date can pose a severe risk to the mason, handyperson, or even anyone nearby.
Fig. 2 – A cutting disc in motion
2. Buy cheap, buy twice.
As you may be thinking of your budget, it’s imperative to know that cheaper grinding discs aren’t of high standards. Most of the time, this is often due to the context of the substandard nature of the abrasive. Cheap purchases might take you back to the market again, searching for another concrete grinding disc. Plus, buying cheap discs can affect your production process negatively. In this regard, we advise masons or handypersons to look for diamond grinding discs for concrete, as diamond tools have proven to be very efficient. Plus, they are quite durable and wear evenly.
3. Bond strength and wheel structure
Discs tend to differ based on the strength of the bond that holds the abrasive and the grain spacing. The grade or strength of the bonding material ranges from A – H (soft), I – P (moderately hard), and Q – Z (hard). It would be best if you noted this when purchasing a concrete grinding disc. The wheel grade also goes a long way to determine the wheel speed, coolant flow, grinding depth, maximum and minimum feed rates, and the like.
Soft-bonded discs release the grains too quickly, which makes the wheel wear out fast. With hard-bonded discs, dull grains cause glazing, which invariably makes the grains wear out soon. Regarding grain spacing, it usually spans from 1(the densest) to 17 (the least dense). Discs that come with less grain density are open-structure discs. Open-structure discs cut more freely and play a vital role in the finish. Plus, they cut broader and deeper with less coolant.
Fig. 3 – Circular saw blade
4. Size and grinding discs
The diameter of a grinding disc can span from 1″ – 20″. It can also range from 0.035″ to as far as ½” as regards thickness. You can use the smallest discs for minor projects such as auto body works. The largest ones can be through thick metal and concrete constructions like railway tracks. Grinding discs also come in different types –
• Cylinder discs
These discs are best for horizontal or vertical spindle grinders. They have no mounting support. Masons use them to create flat surfaces.
• Straight discs
These discs are quite common in most workshops. Handypersons use them for centerless, cylindrical, and surface grinding operations. Plus, you will find them mostly on the bench on pedestal grinders. Masons use them to create slightly concave surfaces.
• Tapered discs
You can use tapered discs for grinding threads and gear teeth. Primarily, it is a straight disc that tapers toward the center of the disc. However, sharp discs can accept higher lateral loads.
• Straight cup disc
You can use this disc to provide an additional radial grinding surface.
• Dish cup disc
These discs do well in jig grinding and cutter grinding.
• Saucer discs
You can use these discs to grind milling cutters and twist drills.
• Diamond discs
Diamond discs are the best for grinding sturdy materials like precious stones, carbide cutting tips, and concrete. Diamond discs are your best bet for concrete as they tend to last longer.
Fig. 4 Grits on a diamond wheel
5. The grit of the concrete grinding disc
The grit refers to the individual size of each grain in the concrete grinding disc. Grit size corresponds to the final screen’s number of openings per linear inch. Invariably, the higher number of grains translates to smaller openings in the screen the grain pass through. Lower numbers such as 9, 15, or 23 depict a disc with coarse grain. Coarser grains go with larger materials. You can also use coarse grains for rapid removal, where the finish is irrelevant. High numbers such as 75, 150, or 180 depict fine grit discs. This grit type imparts fine finishes.
Fig. 5 Abrasive discs
6. Consider the abrasive.
Abrasives come in varieties, and as such, they should also be an essential factor when you’re looking to select a concrete grinding disc. Abrasives have different properties regarding strength, hardness, impact resistance, and fracture toughness. There are two types of abrasives manufacturers use to produce grinding discs. These abrasives comprise several mineral and chemical ingredients.
Also, the formula tends to vary depending on the sturdiness of the material the disc intends to polish, cut, or grind. There are two known types of abrasive grains –
• Conventional abrasives
These abrasives come in aluminum oxide, silicon carbide, and ceramic forms.
• Super abrasives
These abrasives come in diamond and cubic boron nitride forms.
Well, as a mason that works on concrete most of the time, we advise that you go for grinding discs with super abrasives due to their diamond properties. Concrete is a hard material and, as such, would need a diamond grinding disc. On the plus side, you can use diamond grinding discs for concrete on other materials such as granite, cemented carbides, stones, and marbles.
Frequently Asked Questions
We will answer some common questions handypersons or masons tend to ask when purchasing a concrete grinding disc. These answers should put some things in perspective regarding any future decision you want.
What are the available concrete discs on the market?
There are numerous grinding discs on the market. These grinding discs vary in their functions and the hardness of the disc’s material. Grinding discs for wood, metals, diamonds, stones, concrete and the like exist. You must select grinding discs for the materials you want to cut or grind.
What materials can I grind with my concrete grinding disc?
Concrete grinding discs are sturdy cutters, and as such, you can also use your concrete grinding discs for materials like marbles, gemstones, carbide, and the like.
Where can I get the best concrete grinding disc?
NC Cutting Tools is your best bet if you want to purchase the best concrete grinding disc. They are prominent manufacturers of diamond grinding discs for concrete, as well as other diamond tools as well. Most reputable workshops rely on NC Cutting Tools for their quality tools, as they have a track record of manufacturing top-notch diamond cutting tools.
If you’re looking to embark on a concrete project, we advise purchasing your tools from NC Cutting Tools.
With the tips we discussed above, selecting a concrete grinding disc should be much of a hassle as you know what to look out for. However, a whole lot depends on who you’re buying from. In this regard, we recommend NC Cutting Tools as the No.1 manufacturer of quality tools. Don’t forget to wear your safety gear during any cutting/grinding operation. Stay safe!
If you wish to know how a concrete grinding disc works, click here.