Safety when working with a grinder: the secrets of the master

Even the seemingly most innocuous instrument, under certain circumstances, becomes dangerous not only to health, but also to life. In this regard, we will tell you about the most common cases of incorrect operation of the grinder, which can lead to injury. More precisely, we will pay attention to what needs to be done to avoid them..

The grinder, regardless of size, is considered the most dangerous tool for several reasons:

1. A relatively large open area of ​​the rotating element (disc).
2. Lack of a reliable anchor point.
3. Sharp discs (abrasive).
4. High rotational speed for small models and high power for large.

The number of injuries from it exceeds other factors by several times (the closest “competitor” is winter ice). To work fully and safely with it, a certain skill is required, which is acquired during work..

Note.These recommendations are based on a tool that is in good working order and normal operation..

Rule # 1. Skill Comes First

The danger of this tool is determined primarily by the principle of operation – cutting occurs when the rotating disc contacts the workpiece. In this case, the point of contact is the only stationary support, since the tool itself is held by the operator on the weight. In such conditions, even a slight bias can cause a sharp uncontrolled jerk..

How to insure. If you have to work with a grinder for the first time, start with low-power models (disc diameter 115–125 mm). This will help you master the principle of distributing the loads of the included tool. Refuse work that seems dangerous to you.

Rule # 2. Attention to Disc

About 90% of “emergency” cases are due to problems with the abrasive disc (or cut-off wheel), which serves as an activator and a cutter at the same time. Defective abrasive discs are common.

Chipping.This visible defect forms a jag which, when it comes into contact with metal at speed, will cause a sharp jerk. In this case, the operator will not have time to extinguish it due to the high rotation speed. In the best case, after a jerk, the disc will fail. In the worst case, the disk will either fly to pieces at a speed of up to 300 km / h (bullet speed), or the tool will simply be ripped out of the hands with minimal consequences.

Breakdown.This defect may not be noticeable at first glance, but immediately felt when turned on – it starts to “chatter”. A broken disc can break even before contacting the workpiece. Often a break (of a thin disc of 1.5–1.8 mm) occurs during operation, when a grinder with a disc lies on the ground and is accidentally stepped on. If this happened to you or in front of your eyes, inform the operator (since he can be sure that everything is in order with the disk).

How to insure. Only a check before installation and control literally before each launch will give a guarantee of reliability (factory defects are rare). If a brigade is working, the operator of the grinder works only with it and monitors his tool. Discs from a reliable manufacturer (LugaAbrasiv, BOSH, Kronomax) have greater tear resistance than cheap counterparts.

Rule number 3. Each operation has its own disk

A huge number of cutting and grinding wheels are produced at dozens of large and small factories for literally every task. The habitual desire to save money and the desire to do everything with one disk can lead to a hospital bed.

Disk misuse:

1. To save time, plywood or wood that is softer than metal is often cut with an abrasive. At the same time, the disc hardly wears out, and there is no risk of splitting due to the viscosity of the material. However, the high temperature from friction heats the glue and resins and produces corrosive smoke, which, if it gets into the eyes and respiratory system, can disorient or distract the operator..
2. Installing a wood disc on a grinder is prohibited by all manufacturers of this tool. The toothed disc clings to the material better than the abrasive, therefore the resistance force is several times higher. Only a very experienced operator can keep the grinder in such conditions. The identity of the seats of the grinder and circular saw discs, as well as the desire for unhealthy savings, pushes people to this step..
3. Sharpening of metal on the side plane of the wheel leads to a decrease in the thickness and imbalance of the disc. The top layer of abrasive is erased and the fiberglass is exposed. This is very bad. There are corresponding discs for sharpening and processing metal. This also applies to edge grinding..

How to insure. Each disc has a mandatory indication of its scope. If all the inscriptions are in a foreign language, choose another company – there are more than enough of them in each department of the store or on the market. Any form of using cutting and grinding wheels for other purposes (except for a hot plate) – under the responsibility of the operator.

Rule number 4. Calm, attentive, cautious

In the absence of these factors, the operator’s work can become dangerous not only for him, but also for those around him. There are a number of typical situations where an injury can be sustained through carelessness..

Hidden obstacle.On the path of cutting a sheet of metal or a row of reinforcement, there may be something solid (for example, a stone), located under the sheet, that is, invisible to the operator. The disc bumps into it and breaks.

Clamp between supports.“Favorite” mistake of beginners. When positioning the workpiece, pay attention to how the forces are distributed relative to the supports. If you cut between two supports, the edges of the groove will converge and the disc will clamp (the tool will pull out of your hands). The same happens if you cut on a flat plane..

Cut by weight or by weight of the workpiece or loaded structure.One of the most dangerous cases. The metal is quite strong and does not deform up to 80–85% of the cut. Then a sharp movement can occur when the element tends to separate under its own weight. At this point, as a rule, the disc clamps, and the operator requires a lot of composure, strength and dexterity to hold the tool in his hands. Especially if it is work at a height. It is performed by the most experienced workers who are able to measure the distribution of loads in the structure by eye.

How to insure. “Seven times measure cut once”. Check the strength of the base, support. Figure out in advance where the instrument might lead. Do not save time on preparing the workplace – we are talking about health and life. Try to position the workpiece so that the smaller (short) part is in weight.

Rule No. 5. Control “before” and “after” the operation

There are points not directly related to cutting or grinding that you need to pay attention to:

1. Installing the disc. The tool shaft has a thread for a mounting nut. The desire to fix the disc more reliably sometimes suggests tightening it with a special wrench from the kit. This wrench is for loosening the nut. A tightly tightened nut is difficult to unscrew – the key breaks off, knocking your hands. For normal fixation, it is enough to pull it up by hand together with the disc.
2. Turning on the instrument. Before starting, the disc must not come into contact with anything (except the shaft). Otherwise, an uncontrolled jerk is possible. Do not drive the blade into the cut before engaging.
3. Idling. Changing positions, walking and communicating with colleagues with a working tool in hand is a direct path to injury. Turn it off after every operation.
4. Completion of the operation. After cutting or sanding, stop the blade on the wood. Do not put the grinder with a rotating disc.

Most of the precautions not covered in this article can be found in the instructions for the tool. No matter what the “more experienced workers” say, you should not take unnecessary risks, removing protection, working without PPE or a faulty tool. Remember that the construction site is an object of increased danger and your health is in your hands.