How to change drill bit for hand drill
1. Disconnect the power supply of the electric hand drill, pull out the plug of the power line of the hand drill from the socket, and place the drill bit of the hand drill upward and stably.
2. The special key is used for the drill chuck. When removing the drill bit, insert the special key into the drill card, and the gear on the key is aligned with the gear on the drill card.
3. Turn the special key, turn it clockwise for tightening and anticlockwise for loosening. To change the drill bit, you need to put on gloves (thick points), and then hold the gourd mouth of the rubber drill and rotate it anticlockwise to complete the removal of the drill bit. Then rotate clockwise to replace the electric hand drill with a new drill bit.

Safety operation regulations for electric hand drill
1. The shell of electric hand drill must be protected by grounding or neutral line.
2. The electric hand drill wire should be well protected. It is strictly forbidden to drag it to prevent rolling damage and cutting. It is also not allowed to drag the wire into the oil water to prevent the oil and water from corroding the wire.
3. When using, you must wear rubber gloves and rubber shoes; when working in a humid place, you must stand on a rubber pad or a dry board to prevent electric shock.
4. In case of electric drill leakage, vibration, high heat or abnormal sound, stop working immediately and ask electrician for inspection and repair.
5. When the electric drill does not stop l rotation completely, the drill bit cannot be unloaded or replaced.
6. Cut off the power supply immediately when you have a rest or leave the work place.
7. It can't be used to drill cement and brick walls. Otherwise, it is easy to cause motor overload and burn the motor. The key is that there is no impact mechanism in the motor and the bearing capacity is small.

What are the operation precautions of electric hand drill
1. Check the power cord for damage before use. If yes, it must be wrapped with insulating tape. Do not be immersed in water, dragged or trampled, or touch heat source and corrosive medium.
2. For the electric hand drill with metal shell, protective grounding (zero connection) measures must be taken.
3. Before use, make sure the electric hand drill switch is off to prevent the drill from turning suddenly when the plug is inserted into the power socket.
4. Before use, the drill should be idled for 0.5-1min to check whether the transmission part is flexible, whether there is abnormal noise, whether the screw is loose, whether the commutator spark is normal.
5. When drilling, both hands should hold the electric drill tightly, try not to operate with one hand, and should master the correct operation posture.
6. Do not use a bit with a notch, and the downward pressure should not be too large to prevent the bit from breaking.
7. All these actions must be carried out when the power supply is disconnected.
8. Small workpieces must be clamped with the aid of clamps, and then electric hand drill is used.
9. During operation, the drilling force should not be too large to prevent the bit or tapping from flying out to hurt people.
10. Before operation, the drill bit should be carefully checked for cracks or damage, and if found, it should be replaced immediately.
11. Pay attention to the rotation direction and feed direction of the electric hand drill bit.
12. First turn off the power supply and wait for the drill to stop completely before taking the workpiece from the tool.
13. Do not touch the drill bit immediately after processing the workpiece, so as to avoid the drill bit overheating and burning skin.
14. Before operation, the drill bit should be carefully checked for cracks or damage, and if found, it should be replaced immediately.
15. If it is found that the spark on the commutator is large and the electric drill is overheated, it must be stopped using and checked, such as clearing the dirt, replacing the worn brush, adjusting the spring pressure of the brush holder, etc.
16. In order to avoid cutting fingers, ensure that all fingers are removed from the workpiece or bit (tapping).
17. Unplug the power plug in time when not in use. The drill should be stored in a dry and clean environment.

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