Drill bits can be divided into many types according to the materials that they work on. Such as drill bit for wood, drill bit for rocks, drill bit for plastics and so on. In his article, the drill bit for metal is mainly discussed. Since to drill through metal is much harder than to drill through wood, the regular drill bits for wood are not qualified for the work to drill through metal. Drill bits for metal should be made of special materials. Thus its price is higher than ordinary drill bits. And the drill bits for metal may be the most expensive ones. To choose the best drill bit for metal is the first step to do your drilling work. In China, there is a saying goes, if you want to do things well, first sharpen your tool. The drill bit that you can count on for metalworking project is mainly produced by high speed tool steel or hard alloy. In factory, the drill bits that are made of by the first kind of materials are used mainly. Then according to the material that you want to drill holes on, the rotate speed of the drill bit is determined. Sometimes, the coolant may be used to prevent the drill bit from overheating. The high-speed steel drill bits are usually black. Now there are drill bits that has a layer of rare hard metal plated on them. The color of these kind of drill bits is gold.
There are several factors you should consider when to choose the best drill bit for metal.
(1) The machining accuracy. When you choose the best drill bit for metal for your work, you should first consider the size accuracy of the borehole. Generally speaking, the smaller the hole, the smaller the tolerance. Therefore, the drill manufacturers usually classify the drill bit according to the nominal diameter of the borehole.
(2) The processing stability. In addition to considering the accuracy requirement of the borehole, you should also pay attention to the stability of the machine tool when select the drill bit. The stability of machine tool is very important to keep the safety service life, so the working condition of the main spindle, fixture and other accessories of the machine must be checked. Besides, the stability of the drill bit itself should be considered. For example, in general, the rigidity of hard alloy bit is the best, so it can achieve very high processing precision. But the carbide hard alloy drill bit has a poor structure stability, it is very prone to deviate from the proper place.
(3)The cost to drill a borehole. Productivity or processing cost for per hole is one of the main factors to choose the suitable best drill bit for metal. In order to improve the productivity, bit manufacturers are dedicated to study the processing method that integrates multiple operation processes. They want to develop new drilling tools with high rotate speed.
Finally, you should choose the most suitable and the best drill bit for metal according to the kind of metal you will work with.