Q:To do the M4 screw hole, what size holes must be drilled first?

According to my experience in the industry, since you are an aluminum piece, you should use kerosene or kerosene and cutting fluid when you tap. This will make the tapping more smooth and protect the tap and thread. In addition, the general aluminum pieces should be steel wire screw, otherwise, the teeth are easily broken.

Q:Why can't the tap be nitrided? Drill bits are available.

Many imported taps are coated now. In addition to TiN, there are TiCN, TiAlN.

Q:What steel blade drill bit, hardness above 60

A diamond bit is a drill bit for cutting edges. The drill bit is an integral bit, the whole drill bit has no moving parts, the structure is relatively simple, with high strength, high wear resistance and impact resistance, it is one of the three new drilling technologies in the world in 1980s. Field use shows that the diamond bit in the soft - hard strata drilling, have the advantages of high speed, more footage, long service life, stable operation, less accidents, downhole wellbore quality etc.. The diamond bit not only can be used for a long time, but also can be reused. The diamond bit recovered from the factory can be used almost as well as the diamond bit produced by the factory. It can save drilling cost in large amount.

Q:What drill is used for machining holes with a diameter of 3mm?

In general, if the drill pointed to the comparison of the grinding, it is recommended to be smaller than the final hole 0.10mm, of course, this is the processing of steel parts, plastic and other processing holes will shrink back, generally take a little larger diameter. If the final size of the strict requirements, it is best to drill rough, such as 2.5 of the drill bit, and then 2.8-2.9 drill reaming, and finally reaming, precision reaming, usually with 3.0mmD5-D6 class. Drill what specifications have, in general, the first series of multi-point, second, third series less, large dosage, you can find manufacturers custom. Can not find the words, you can buy a larger diameter of their own in centerless grinding or grinding on the outer circle to change, but the effect will be worse, the drill has inverted cone, not necessarily grinding, and need experience.

Q:What does the cutting depth of the drill mean 3D?

That is, the diameter ratio of the drill, such as 3D, and the diameter of the drill is 20MM, the effective drilling depth is 60MM

Q:What is a water bit?

This kind of drill is specially drilled on reinforced concrete.

Q:With what drilling steel

Tungsten steel (hard alloy) with high hardness, strength and toughness, good wear resistance, heat resistance, corrosion resistance and a series of excellent performance, especially high hardness and wear resistance of it, even at a temperature of 500 DEG C also remained unchanged, at 1000 degrees C still have high hardness.

Q:How do you get yellow on the surface of the drill bit?

The Yellow above the drill is not baked. It is a kind of coating which is evaporated and ionized by the titanium metal in the high temperature and high vacuum environment. At the same time, the coating is added to the metal surface after the reaction of the reaction gas. It is also called PVD coating.

Q:Grinding the drill bit, how can grinding, and the method of quick crash is what ah?

By the back edge grinding behind. This is the slow grinding of the entire flank from the edge of the bit. It is easy to dissipate heat and grind. Based on the stability of the consolidation of one or two of the formula, the drill can be gently contact for a relatively small amount of grinding wheel, grinding, grinding to observe the uniformity of the spark, to adjust the size of the pressure, and bit cooling. When the cooling start again after grinding, to continue to set the formula to the one or two position, it is often in the beginning is not easy to grasp, often can't help to correct change their positions.

Q:What's the difference between a drill bit and a tap?

The drill bit is specially used for drilling, while the tap is used for tapping