Choosing a cutting disc for metal grinder

The grinder, or how to call it correctly, the angle grinder is especially popular in almost all construction specialties.
Initially, it was only used for grinding, later it began to be used more as a cutting tool for metal and stone. As a consumable material in the grinder, the so-called cutting wheels are used. They can be for various purposes, but in this article we will focus on cutting wheels for metal. First, some general information:

Cut-off wheels are analogs of the grindstone used by our ancestors to sharpen the cutting edges of tools. The difference is that the cutting wheel is made artificially, it is made in the form of a circle (for sharpening from a rotating engine) and is made of small thickness so that the cut is small.

Cutting wheels are made of a special abrasive crumb, which is glued together with a special adhesive composition.

Depending on the class of the grinder, cutting wheels come in various sizes. The most common circles with a diameter of 115, 125, 150 and 230 mm. There are discs of a larger diameter, but they are put on the so-called cutting machines - you simply cannot handle such a large grinder manually, you warp the disc and it will fly apart and injure the worker.

The inner diameter of the circle is unified, so you should not worry that it will not fit the shaft of your grinder. The disk is clamped on the shaft with the help of two special washers on the thread, which securely fix the cutting wheel, and due to the reverse threading, they do not allow it to unwind.

Choosing the right cutting disc

In order not to confuse a disc for metal with, for example, a disc for stone, manufacturers apply color marking. If the circle is blue, then it is for metal, if it is green, it is for stone. Additionally, information is applied to the surface of the disk regarding the manufacturer, the diameter and thickness of the disk.

So you have decided and decided to purchase a cutting disc for metal of the desired diameter. The next point is the choice of the manufacturer. Someone immediately buys expensive BOSCH discs, while someone, on the contrary, takes it cheaper, for example, Lugovskie. What is better?

As practice shows, if you buy abrasive discs for metal, then it is not a fact that expensive ones are better. The fact is that disc wear largely depends on the ability to cut metal, rather than on the quality of the disc. If you constantly warp it, then it will be erased very quickly, if you cut it correctly, then a cheap disk will last for a long time. It is also important to know what kind of material you will have to cut - thin sheet metal or thick metal such as channel walls.

If the metal is thin, then it is better to choose a more expensive and stronger disc. For a thick wall, on the contrary, it is better to take discs with a looser structure. If you take a durable disk, then it will not cut the metal, but will “lick” it. The loose structure grinds faster and cuts through thicker metal more easily.

The thickness of the disk is also important. For use on the most popular grinder size for a 125 mm disc for cutting thick metal (corners, fittings, channel bars), it is best to choose a 1.6 mm thick circle. Thinner (1.2 or 1 mm) with strong pressure starts to play and may collapse. For a thin sheet or profile for drywall, on the contrary, it is better to take a thinner cutting wheel. By the way, the thicker the circle, the greater the load on the grinder's engine.

For a large grinder (for 230 mm discs), 2.5 mm thick discs are best suited for thick metal. They hold the plane well enough and do not play. Thinner cutting discs will fit sheet material up to 2 mm thick.