1. The quality of the machine tap is not good: the main material, CNC tool design, heat treatment, machining accuracy, coating quality, etc. For example, if the size of the tap cross-section transition is too large or the transition fillet is not designed to cause stress concentration, it is easy to break at the stress concentration when used. 5 tapping material issues: imperfections, imperfections, local hard points or pores, resulting in an instant loss of balance and break the tap. 9. Operators' skills and skills do not meet the requirements: All of the above problems require the operator to make judgments or give feedback to the technicians. However, most of the operators in the country do not pay enough attention. For example, when processing a blind hole thread, when the tap is about to touch the bottom of the hole, the operator does not realize that he still feeds at the tapping speed when not reaching the bottom of the hole, or forcibly breaks the thread when the chip is not flowing smoothly. . It is recommended that operators strengthen their sense of responsibility. China leading manufacturers and suppliers of Forklift Solid Tyre,Forklift Solid Tyres, and we are specialize in Agricultural Solid Tyres,Industrial Solid Tyres, etc. Forklift Solid Tyre,Forklift Solid Tyres,Agricultural Solid Tyres,Industrial Solid Tyres Zhejiang Hengbang Rubber Products Co., Ltd. , https://www.hbrubberproducts.com
The transition of the cross-section at the intersection of the shank and the blade is too close to the weld, resulting in a complex stress stress and superposition of the stress concentration at the cross-section transition, resulting in greater stress concentration, resulting in the tap breaking during use. For example, the heat treatment process is improper. When the tap is heat treated, if the preheating without quenching before quenching, quenching overheating or overheating, not tempering and cleaning prematurely may cause cracks in the tap. To a large extent, this is also an important reason why the overall performance of domestic taps is not as good as that of imported taps.
2. Improper selection of the machine tap: For taps with too high hardness, high-quality machine tools taps should be used, such as cobalt-containing high-speed steel taps, hard alloy taps, and coated taps. In addition, different tap designs are used in different workplaces. For example, the number of flutes, the size, and the angle of the taps of the machine tool have an impact on the chip removal performance.
3. The machine taps do not match with the processed materials: this problem has been paid more and more attention in recent years. In the past, domestic manufacturers always felt that imports were good and expensive, but they were actually suitable. With the increasing number of new materials and the difficulty in processing, in order to meet this need, the variety of tool materials is also increasing. This requires choosing the right tap product before tapping.
4 bottom hole diameter is too small: for example, when processing ferrous metal material M5 × 0.5 thread, with a cutting machine tool tap should use a diameter of 4.5mm drill bit bottom hole, if you use a 4.2mm drill bit to make a bottom hole, when tapping The part of the tap that must be cut must increase, which in turn causes the tap to break. It is recommended to select the correct diameter of the bottom hole according to the type of tap and the material of the tapping material. If the drill bit is not fully qualified, you can choose the largest one.
6. The machine tool does not meet the accuracy requirement of the tap: The machine tool and the clamping body are also very important, especially for high quality taps, as long as a certain precision of the machine and the clamping body can play a tap performance. Common is not enough concentricity. When the tapping starts, the starting position of the tap is incorrect, that is, the spindle axis is different from the center line of the bottom hole, and the torque is too large during the tapping process, which is the main reason for the tap breaking.
7. The cutting fluid, the quality of lubricants is not good: Many companies in this country have begun to pay attention, many companies that have purchased foreign tools and machine tools have a very profound experience, cutting fluid, lubricant quality problems, processed products Quality is prone to glitches and other adverse conditions, and life will be greatly reduced.
8. Cutting speed and feed rate are unreasonable: When machining problems occur, most users in China reduce the cutting speed and reduce the feed rate. As a result, the tapping force of the tap is reduced, and the threading accuracy of its production is greatly reduced. This increases the roughness of the thread surface, the thread aperture and the thread accuracy are not controlled, and burr and other issues are certainly more inevitable. However, if the feed rate is too fast, too much torque may cause the tap to break. The cutting speed during machine attack is generally 6-15m/min for steel, 5-10m/min for hardened steel or hardened steel, 2-7m/min for stainless steel, and 8-10m/min for cast iron. In the same material, the tap diameter is smaller and the tap diameter is larger.
From the above, it can be seen that the cause of the tap fracture can be described as varied. Machine tools, fixtures, workpieces, processes, chucks, and knives are all possible. On paper alone, the real reason may never be found. As a qualified and responsible tool application engineer, the most important thing is to go into the scene, not just imagine. For the simplest example, if the tap cone is too long, the tap will break when hitting the bottom of the bottom hole. If you don't go deep into the site, just guess how the tap performance, workpiece material, machining process, etc. are known.
When I first started, I couldn't think of dreaming, but there were customers who had this problem that you might think was extremely low, but you have to face it.
In fact, neither the traditional tapping device nor the expensive CNC device can solve the above problems in principle. Because the machine does not recognize the working conditions of the tap and the most suitable torque required, it will only repeat the processing according to the preset parameters. Only when the machined part is finally detected with a thread gauge is a failure found, but it is too late to find it.
Even if it is found to be useless, the scrapped and expensive components have to be scrapped, and substandard products have to be thrown into substandard products. Therefore, in large-scale enterprises for large, expensive, and precise workpiece processing, even if it is expensive to use imported taps do not use domestic, because once the tap breaks, the workpiece scrapped, the price paid is quite large. The foreigners are amazing, and the price of taps remains high. It's sad to see that a considerable part of the company's profits have been taken away by foreigners. Hey, people still need to work hard!