How to buy CNC drilling machine drill

How to buy CNC drilling machine drill?

CNC drilling machine drill bit selection methods:
1, CNC drilling machine drill bit types and characteristics:

PCB drilling with straight shank twist drill bits, twist drill head fixed handle and fixed handle spade (undercut) drill bit. Straight Shank Twist Drill head mostly for single-head drilling machine, drilling of printed circuit board or a simple single panel, now in large circuit board production plant has been rarely seen, the drilling depth of up to 10 times the drill diameter. Laminated substrate is not high in the case of drilling with drill sleeve to avoid bias. At present, most manufacturers use CNC drilling machine, CNC drilling machine using a fixed shank carbide drill bit, the feature is to automatically replace the drill bit. High positioning accuracy, do not use the drill sleeve. Large helix angle, chip speed, suitable for high-speed cutting. Flutes range in length, is an inverted cone drill diameter, drill hole wall friction with the small, high quality drilling. Common drill shank diameter 3.00mm and 3.175mm.
2, CNC drilling machine drill material:

PCB drilling with carbide drill bits are generally used as epoxy glass fabric copper plate for re-tool wear particularly fast. Carbide is tungsten carbide powder as the so-called matrix, cobalt powder as binder by the pressure, sintering. Usually 94% WC, 6% cobalt. Because of its high hardness, very wearable, there is a certain strength, suitable for high-speed cutting. But toughness is poor, very brittle, in order to improve the performance of cemented carbide, and some carbon substrate used in chemical vapor deposition of a layer of 5 to 7 microns special hard titanium carbide (TIC) or titanium nitride (TIN), it has a higher hardness. Some ion implantation technology, titanium, nitrogen, and carbon into the depth of its base must not only improve the hardness and strength, and regrinding the drill bit into the ingredients when they can move into. Some physical methods used to generate the bit at the top of a layer of diamond film, which greatly improves the hardness and wear resistance of drill. Carbide hardness and strength, not only with the ratio of tungsten carbide and cobalt, but also with the powder particles. Ultra-fine particles of solid carbide drills, the tungsten carbide phase, the average grain size of 1 micron or less. This drill is not only high hardness and compressive and flexural strength are improved. In order to save costs now handle many bits are welded structure, the original carbide drill bit as a whole are now drilling the rear handle with a stainless steel, greatly reduced the cost of different materials but due to its dynamic concentricity less than the overall hard alloy drill, especially in small-diameter side.