the HSS rail core drill in the hole processing can save time, save labour, improve work efficiency. About to annular cutters As the name suggests is that there is no drill core drill, cutting tool according to the structure called the name of As a cutting tool that people use the twist drill head has 100 years history. As the core part of the twist drill drill head is completely negative cutting angle, cutting resistance to big, so the first twist drill cutting force 50% 60% is due to a result of drill core drilling. Coupled with steel factor, it can not be done the first big twist. Processing of a larger number of deeper holes drilled holes from the beginning to be expanded step by step, until the bore size up to meet the requirements. The advent of the annular cutters cutting expanded the scope of the use of a relatively small power can be deep-hole machining of large holes, you can also put the size of the annular cutters is large scale only in cutting the use of better or best steel, not only reduces the manufacturing cost, the monument also means that the processing technology can become possible. My company has been trying to study large hole hole processing technical problems, not only design and development of small size, high-speed tool steel annular cutters and the formation of large quantities of production capacity in steel structure, the plate and in the railway has played a very large role, in addition to development and design of large-size high-speed steel and carbide drill bit hollow, it was according to the role of drill bits, also known as nesting or core drill bits. Our technical staff developed the annular cutters is from the beginning in 1985, in the middle through many tortuous, failed several times in 1989 to take enforcement measures to sub-chip developed by a successful, due to the use of units of equipment vehicles do not match there has been no mass production. Imitation of foreign units in 1998, the success of drilling machines, we are supporting and gradually increased its production amount. Now, in addition production using special annular cutterss, but also the production equipment used in the general-purpose large-scale annular cutters, it was also known as Nesting knife. Small-scale hollow drill under normal circumstances do high-speed tool steel is roughly φ16 φ50 range. We use high-speed tool steel with M2, M35, and three kinds of high-performance, respectively, to adapt to different cutting environments. φ50 above we do advocate the use of carbide materials, carbide are welded and Clamping the two, we propose the use of large-size hollow drill machine Indexable carbide blade, so that help reduce production costs, saving raw materials, improve work efficiency and give full play to the superior carbide cutting blade. Annular cutters has many unique advantages, especially in large quantity and size of the depth of drilling a long time, the use of its superior performance, will be able to fully play out, you can greatly improve work efficiency, it is common twist drill head and cutting tools in general can not be replaced, large size of the carbide machine Indexable blade-style hollow drill will also be in the power generation and national defense construction, played a significant role.