1, the choice of drill head size: With the increase in the size of the drill head, the price will also increase, the size of the drill head for home use is generally 20mm will be sufficient.
2, electric drill additional features to choose: the same model, there will be some additional features, for example, the model has R that the drill can be forward and reverse, the benefit is that when the positive rotation does not work, can be converted to reverse; model has E that the drill can be speed, when not need high rate can be adjusted to low-speed operation.
3, the use of electric drill: indoor ceilings, for example, ceilings made of reinforced concrete, such as the use of impact drills to drill holes will cost a lot of gas, but the use of its wall will not be the case, so the impact drill is suitable for daily use in the home, but for the drilling staff, the hammer drill should be preferred. In the wall, the hammer drill will be more labor-saving than the impact drill, the key is that the structure and working principle of the two is different, the impact drill in the process of using the human need to constantly apply force to make it turn, while in the use of the hammer drill, only a little force at the beginning to make the drill automatically go forward.
4, Observe the outer packaging of the electric drill. The outer packaging of the tool should have a clear pattern, no breakage, a strong plastic box, and the buckle to open the plastic box should be firm and durable.
5, observe the appearance of the drill, the appearance of the tool should be uniform in color, the surface of the plastic parts without obvious shadow silk and dents, there should be no scratches or bump marks, the assembly misalignment between the shell parts ≤ 0.5mm, aluminum casting coating smooth and beautiful without defects, the entire surface of the machine should be free of oil and stains. When held by hand, the self-feeling feels better in hand, and the handle of the switch should be flat. The length of the cable line should generally be not less than 2 meters.
6, check the nameplate and instructions of the electric drill, the nameplate parameters of the tool should be consistent with those on the 3C certificate. Instructions should have the manufacturer and production plant's detailed address and contact information. The nameplate or certificate of conformity should have the batch number of the product traceable.
7, hold the drill by hand, turn on the power, frequent manipulation of the switch by hand, so that the tool frequently start, observe the tool switch on and off function is reliable. At the same time, observe whether there are any abnormalities in the TV and fluorescent lights at the site. In order to confirm whether the tool is equipped with an effective radio interference suppressor.
8, the electric drill power run for one minute, running with the hand, the hand should not obviously feel any abnormal chatter, observe the commutation spark, its commutation spark should not exceed the level, generally from the inlet of the tool to look in, in the commutator surface should be no obvious arc. When running, there should be no abnormal noise.