How to change a disc on a grinder without a key?
Method 1. Use a gas wrench
Grasp the nut with an adjustable pipe wrench and loosen it carefully, without applying great force. Disadvantage: you can crush the nut, break the rotation lock
Method 2. Make a homemade key for the grinder. To do this, you need a long nail (at least 100 mm). It is necessary to cut off the cap, the point and give the nail a U-shape. It should be bent in such a way that the “tool” stands fall into the holes of the flange. If the nut is tightened tightly, insert any metal bar between the posts of the nail and, grasping it with both hands, rotate the structure in the direction of the circle's movement. At this time, you need to press and hold the spindle lock button. The method is safe, but it takes time and additional tools - a hacksaw, a vice, a hammer.
Method 3. Tapping with a chisel. Before changing the disc, you can treat the spindle shaft with WD-40 fluid and wait at least 15 minutes. Then put the tip of a thin chisel at an angle to the hole of the flange nut and gently tap it over the entire surface of the hole with a metal hammer. Sooner or later, thanks to gentle tapping, the nut will slip off, and it will be possible to unscrew it manually. The disadvantage of this method is that you can damage the holes and spoil the flange.
Method 4. Heat the nut. If it is difficult to unscrew the nut of the angle grinder by hand, you can heat it up a little with a gas burner or autogenous gun. Unscrew the flange with gloves so as not to burn yourself. This is the most risky of the proposed methods. It is possible to overheat the bearings and oil in the angle grinder gearbox.
Finally, I would like to mention a few important points regarding replacing a disc on a grinder.
- On the angle grinder, you need to install circles of a suitable size. It is necessary to strictly observe safety precautions and in no case remove the protective cover in order to install a disc of a larger diameter. When choosing a disc, you need to take into account the model of the power tool, its power, spindle rotation speed.
- Due to the disc rotating at high speed, work hardening forms on the protective casing of the angle grinder. Therefore, when changing a disc, remove and clean the casing.
- In some models of grinders, washers are provided so that the disc does not get stuck between the flanges. At least the support flange can be fitted with a rubber washer. Instead of factory fasteners, you can cut cardboard, rubber or plastic spacers. You need to use 2 spacers: between the support flange and the disc, between the disc and the nut.
- Do not forget: if the circle rotates clockwise, then the nut is also unscrewed clockwise and tightened counterclockwise.
- If you do not want to buy a new key, install a Bosch quick-locking nut on the grinder - you can easily unscrew it by hand.
The main thing is that when changing a disc on a grinder, do not violate safety precautions and perform all manipulations with the tool turned off from the network.