Carbide Drill Bit Best Choice
It is believed that the drilling process must be carried out at a lower feed rate and at a cutting speed, which is correct at the processing conditions using ordinary drill bits. Nowadays, with the advent of carbide bits, the concept of drilling has changed.
In fact, by correctly selecting the right carbide bit, you can greatly improve the drilling productivity and reduce the cost per hole.
When selecting a carbide bit, it is first necessary to consider the dimensional accuracy requirements of the drilling process. In general, the smaller the machined aperture, the smaller the tolerance. As a result, drill bits are usually classified according to the nominal diameter of the hole to be machined. In the above four types of carbide drill, the overall carbide drill processing accuracy of the highest (φ10mm overall carbide drill tolerance range of 0 ~ 0.03mm), so it is the best choice for processing high-precision holes; Welded carbide bit or replaceable carbide crown drill bit tolerance range of 0 ~ 0.07mm, more suitable for general accuracy requirements of the hole plus
The drill bits of the hardened indexable inserts are suitable for heavy duty rough machining, although their processing costs are usually lower than those of other types of drills, but their machining accuracy is relatively low, with a tolerance of 0 to 0.3 mm Drill diameter ratio), so it is generally used for the accuracy of the hole is not high processing, or need to follow the finishing hole.
In addition to considering the drilling accuracy requirements, the choice of drill bits need to consider the stability of the machine. The stability of the machine is critical to the safe life and drilling accuracy of the drill bit, so it is necessary to carefully check the working conditions of the machine tool spindle, fixture and accessories. In addition, the stability of the drill itself should be taken into account.
The overall carbide drill has the best rigidity and therefore achieves high machining accuracy. While the carbide indexable bit drill bit structure stability is poor, prone to skew. Welded carbide drills and replaceable carbide crowns are made of two symmetrical cutting edges that are self-centering, and this has a high stability of the cutting edge design so that it does not need to be cut into the workpiece Reduce the feed rate, only when the drill tilt installation and the workpiece surface into a certain angle when the cut, it is recommended drilling, drilling will be reduced when the feed rate of 30% to 50%. As the drill bit of this type of drill can produce small deformation, it is very suitable for lathe processing; and the overall carbide drill bit because of the brittle, for the lathe processing easier to break, especially when the drill bit centering poor When it is so.