Sawing Technology Drives the Development of Precision Machining

What is a Hacksaw?

A hacksaw is mainly used for sawing metal materials, but also for sawing small pieces of wood, plastic products, etc., and sometimes for cutting cables and wires. Common hacksaw frames are available in two types: adjustable length and fixed length, and are made of steel plates or steel pipes.

A hand hacksaw is a common tool for fitters, which can cut small-sized round steel, angle steel, flat steel, and workpiece. The hacksaw consists of a saw frame and a saw blade. When using the saw blade, install the saw blade on the saw frame. Generally, install the saw blade with the tips of the teeth facing forward. However, if you find that it is easier to draw the teeth during use, install with the tips of the teeth facing toward you. This will prolong the service life of the saw blade. After the hacksaw is used, the saw blade should be removed or the tension nut should be loosened, to prevent the saw frame from being deformed. Blades commonly have from 18 to 32 teeth per inch. Courser blades that have less teeth per inch are used for cutting softer or courser materials, while finer blades with more teeth per inch are used for cutting finer and harder materials.

What is a Power Hacksaw?

A chainsaw is a cutting tool that uses electricity as a power to cut wood, stone, steel, etc., and has sharp teeth on the edge. Divided into fixed and portable, saw blades are generally made of steel, with round, bar, and chain types.

Types of Power Hacksaw and Their Selection Point

A power hacksaw is commonly used by lumberjacks, with teeth designed to be attached to a chain to facilitate cutting wood. It usually judges the scale suitable for the operation according to the length of the chain plate, which can be mainly divided into small, medium, and large.

1. Small Power Hacksaw: For light work
   Products with a chain plate length of fewer than 8 inches (25cm) are small chainsaws suitable for gardening work such as trimming branches and leaves. It is usually divided into two types: plug-in type and rechargeable type, which can be freely selected according to the situation of the job site. Also, due to its small size and easy handling, it is a good entry-level option.
2. Medium Power Hacksaw: The Most Versatile
   The length of the chain plate of the medium-sized chainsaw falls between 8 to 14 inches (25 to 40 cm). Due to the full power and the choice of power supply methods, consumers can easily find the type that matches the purpose. For example, when it is necessary to control the air volume and sound volume for gardening work, you can choose the electric model; and in the mountains and outdoor work where it is difficult to ensure the power supply, you can choose the engine model.
3. Large Power Hacksaw: For Large Job Sites
   A large chainsaw is a model with a chain plate longer than 14 inches (40 cm). Most of them have powerful horsepower, and their power type is mainly engines, so they can cut items that are difficult for medium and small machines such as thick trees, and can greatly improve work efficiency in difficult job sites such as logging. However, the operation of large chainsaws is very difficult, and the chainsaw itself has certain dangers. Based on safety considerations, it must be operated by professionals.

Market Overview of Sawing Technology:

Precision manufacturing has become an irreversible trend in global machining. Not only do consumer electronics products have this demand, but industry, aerospace, construction, transportation, and equipment manufacturers are also moving towards more sophisticated manufacturing. On the other hand, the components and materials involved in precision machining are more diverse than in the past, such as more powerful composite materials, which not only need to achieve higher precision but also the performance and output are the items that the industry cares about. Therefore, how to meet the needs of the industry and break through this challenge, the improvement of processing technology is a key link.

With the diversification of materials being sawn, and the demand for high-speed sawing, the demand for tungsten carbide saw blades has also increased in recent years. Tungsten steel and carbon particles are welded together with a base metal to form the blade. Tungsten carbide band saw belts can achieve more than twice the cutting speed of ordinary saw belts and produce a smoother sawing surfaces. They cost more than three times what bimetal saw belts cost, but the sawing life can be expected to be much longer than this. Because tungsten steel is very hard and brittle, vibration of the band saw machine during sawing can seriously affect the sawing life of the tungsten steel blade.

What are the Application Fields for Hacksaws?

Nowadays, to meet the requirements of high-speed sawing, new technologies are being incorporated in the surface coating of saw belts, and sine wave feeding mechanisms, with intelligent feeding and monitoring technology have been successively applied to the new generation of band saws.

Band sawing applications include steel structures, bridges, construction, equipment manufacturing, machining, precision technology, automobile manufacturing, air transportation manufacturing, marine shipping manufacturing, petrochemical equipment, mold manufacturing, and wind power generation.

Recently, due to the demand for many composite materials in the aerospace and automotive industries to achieve the purpose of energy-saving and environmental protection, the demand for precision cutting of composite materials (such as honeycomb, glass fiber, and carbon fiber composite materials) is also increasing. The annual output value of the sawing machine industry can reach billions of Taiwan dollars.

Global Sawing Machine Development Trends: High Speed and Intelligence

The world's major producers of bimetal band saw blades are Europe, the United States, Japan, and Germany. At present, the bimetallic band saw blade market is mature and stable, and the growth in demand mainly comes from emerging economies such as China and India. In recent years, due to the increasing demand for high-speed and difficult-to-cut materials, the selection of cutting conditions depends on experience, and the use of improper cutting conditions will reduce the production rate and increase the wear and tear of the saw band. Optimizing the cutting conditions to increase the cutting rate and prolong the service life of the saw blade is an important way to reduce cutting costs and improve efficiency. Therefore, the development of high-speed and intelligent sawing machines is the current global development trend.

In recent years, the development of intelligent band saw machines has also become increasingly competitive. From understanding the sawing conditions, to the monitoring and troubleshooting of the machine, new intelligent developments are improving the performance of band saw machine tools, but a major problem bandsaw still face is the processing of the blades. Because the saw belt itself has a long tool path with few support points, measurement of sawing conditions is difficult. So, although the band saw machine itself is not as high priced as that of general tools, the unstable conditions under which the belts operate create challenges in the design of belts. Therefore, developing effective, cheap, and reliable blades is a present focus of bandsaw blade development.

Because high-speed band sawing increases the risk of the vibration of the saw belt during cutting, it will increase the load loss of the tool. The design must be simplified to achieve a higher degree of shock resistance, strengthen the effective support of the tool, and increase the rigidity of the saw bow. Due to the wide variety of materials sawn by the band saw machine, it is necessary to select the corresponding saw band for different sawing materials and sawing conditions and adjust to the appropriate sawing conditions. Traditionally, operators with experience will know whether a cut is normal not, however, operators without deep experience can use the saw under conditions that can reduce the life of the saw belt, so an intelligent system is highly beneficial. When cutting conditions are optimized, the life of the saw belt is extended, high-efficiency sawing is achieved, and labor and costs are reduced.

Because the band saw operates under continuous cutting, the design of the cutting teeth on the saw belt is critical to performance. The research and development of special tooth profiles can assure that the cutting force on each tooth is equal and consistent, which is a key to achieving high efficiency and long saw belt life. Protective coating technology can also reduce sawing resistance and protect the geometry of the saw teeth. However, this technology is being newly developed and there are not many saw blades with protective coatings at present.