Safety when working with the grinder. Secrets of the master

Even the most seemingly innocuous tool in some circumstances, it is dangerous not only for health but also for life. In this regard, we describe the most common cases of improper operation of grinders, which can lead to injury. More precisely, we pay attention to what you need to do in order to avoid them.
The grinder, regardless of size, is considered the most dangerous for several reasons:
1. A relatively large open area of the rotating member (disc).
2. The lack of reliable reference point.
3. Chopping disks (abrasive).
4. The high speed rotation of small models and large capacity major.
The number of injuries from it exceeds the other factors several times (the nearest “competitor” — winter ice). For proper and safe use of it requires a certain skill which is acquired during operation.
Note. These references belong to a working tool and work under normal conditions.

Rule # 1. Skill in the first place
The danger of this tool is determined primarily by the principle of work — cutting occurs during the contact of the rotating disc with the workpiece. The contact point is the only stationary support, as the instrument is held by the operator on the weight. In such circumstances, even a small misalignment can cause sudden uncontrolled jerk.
How to insure. If you have to first work with the grinder, start with small models (disc diameter 115-125 mm). This will help to master the principle of load distribution of the included tool. Refuse work that you think is dangerous.

Rule # 2. Attention to disk
About 90% of “emergency” cases have problems with grinding wheel (or cutting circle) which serves as an activator and cutter at the same time. Work with a defective grinding wheel — a common case.

Skol. This apparent defect forms a notch, which in contact with metal at speed will cause a sharp pull. The operator will not have time to extinguish it because of the high rotation speed. In the best case, after breakthrough a drive fails. At worst, the disk is either smashed to pieces at speeds up to 300 km/h (velocity), the tool will simply pull out from the hands with minimal consequences.
Breakdown. This defect may not be noticeable at first sight, but immediately felt when you turn it begins to “chatter”. A broken disc may collapse before contact with the workpiece. Often fracture (a thin disk of 1.5–1.8 mm) is in the process of operation when the angle grinder with the disc lying on the ground and accidentally stepping on it. If this happened to you or your eyes, tell the operator (because he can be sure that with a disk everything is in order).

How to insure. Only pre-installation check and control literally before each run ensures the reliability (factory defects are rare). If team works, the operator of the grinder only works with her and monitors her instrument. Drives a reliable manufacturer (LugaAbrasiv, BOSH, Kronomax) have a greater tear resistance than cheaper counterparts.
Rule # 3. For each operation has its own drive
A huge number of cutting and grinding wheels are produced in dozens of large and small plants literally for every task. A habitual tendency to save and the desire to do all in one disc can lead to a hospital bed.

Disk usage not to destination:
1. To save time, often abrasive sawing plywood or wood that is softer than the metal. Disc almost no wear, and there is no risk of a split due to the viscosity of the material. However, the high temperatures from the friction heats the glue and resin and is acrid smoke, which, when applied to the eyes and respiratory system may cause disorientation of the operator or to distract him.

2. Setting on the grinder disc for wood is prohibited by all manufacturers of this instrument. Gear drive is better clings to the material than the abrasive, so the drag force is increased. Hold the grinder in such conditions can only very experienced operator. The identity of seats, disc grinders and circular saws, as well as the desire for unhealthy economy is pushing people to take this step.

3. Sharpening metal on one side of the circle leads to a decrease in thickness and the unbalance disk. Erased the top layer of abrasive to expose the fiberglass. This is very bad. For grinding and metal machining is the appropriate disks. This also applies to the grinding edge.

How to insure. Each disk must be specified the scope of its application. If all labels in a foreign language, select a different firm — in every Department in the store or on the market their is more than enough. Any form of use of cutting and grinding wheels for other purposes (in addition to stand under the hot) is under the responsibility of the operator.
Rule # 4. Calmness, attentiveness, caution
In the absence of these factors in the operator’s job can be dangerous not only for him but also for others. There are a number of typical situations, when the injury can be to inadvertently.

The hidden obstacle. On the path of the cut metal sheet or series of valves can be something solid (e.g. a stone), located under the sheet, i.e., invisible to the operator. Drive bumps into it and rupture occurs.
The clamp between the supports. “Favorite” rookie mistake. When setting the workpiece note allocation of effort with respect to the supports. If the cut between two supports, the edges of the groove come together and the disc is clamped (the tool will pull out from the hands). The same happens if to cut on a flat plane.

Cut on weight or under the weight of the workpiece or of the loaded structure. One of the most dangerous cases. Metal is quite durable and does not deform until the passage of 80-85% of the cut. Then it may be a sharp movement, when the element under its own weight tends to separate. At this point, as a rule, disk clamps, and operator requires great self-control, strength and dexterity to hold the tool in his hands. Especially if it is work at height. It is performed by the most skilled workers, able to eye to measure the load distribution in the structure.
How to insure. “Seven times measure — cut once.” To check the strength of the base support. To estimate in advance where the novel tool. Not to save time to prepare the workplace — it is about health and life. Try to put the workpiece so that a smaller (short) from parts was on weight.

Rule # 5. Control “before” and “after” operation
There are moments not directly related to cutting or grinding, you should pay attention:
1. Disk installation. On the shaft of the tool has a thread for mounting screws. The desire to reliably fix the drive sometimes suggests to tighten it with a special key from the kit. This key is used to loosen the nut. Much covered the nut is difficult to Unscrew the key breaks, knocking hands. For normal fixing her enough to tighten by hand with a disk.
2. The inclusion of tool. Before the start of the disk should not be in contact with anything (except the shaft). Otherwise an uncontrollable jerk. Do not put the disc in propyl to include.
3. Idle. Changing position, walking and socializing with colleagues with a working tool in the hands — a direct path to injury. Turn it off after each operation.
4. The completion of the operation. After cutting or grinding, stop the disc on a tree. Do not place the grinder with a rotating disc.

The majority of precautions not addressed in this article, you will find in the instructions to the tool. No matter what “more experienced workers”, it is not necessary to take undue risk, pick protection, working without PPE or faulty. Remember that construction is a high risk and your health is in your hands.

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