How to Buy Impact Drill?

When buying impact drill, how to buy? Be sure to choose the most appropriate impact drill.
First, we should know the principle of the impact drill, impact drill is to rely on rotation and impact to work. Impact drill, as a common power tool, is often used in drilling, and drilling bricks, but can not drill concrete.
1.Impact drill size choice: impact drill price is often proportional to the size, the bigger the size, the higher the price. Before the purchase, we must take into account the specific use of impact drill, select a suitable.
2.Additional features of choice: Now most of the products on the market in order to increase customer loyalty, will develop many functions, some of these features may not be used, we should choose according to the actual situation.
3.If the tools are usually more care, buy a little cheaper domestic products, as long as they are careful to use, is more durable.