In the field of metal sawing, when users are faced with the choice of sawing processing methods, they often ask a question: “Which processing method is suitable for my situation? Should I choose a band saw or a circular saw?” If the processing method is wrong, the company’s Business development or cost control may be affected in the long term.
Band sawing has always been considered the main processing method for metal sawing, and over the years, many sub-sectors of this sawing technology have made great progress, such as:
✦Bundle sawing technology, feed control technology using servo drive
✦Using gear motor to realize low-speed and high-torque sawing main drive technology
✦CNC technology for repetitive work
✦High-precision high-speed carbide band saw blade manufacturing technology
✦High-precision sawing technology for difficult-to-cut materials
The above items are just a few of the features and benefits of today’s band saw technology development.
If the circular sawing machine is used with a good quality cold saw blade, it has the characteristics of high sawing precision and high sawing efficiency.
Basic manual circular sawing machines can perform simple, small-batch sawing of a variety of materials, while automated closed circular sawing machines are very suitable for large-scale production and application scenarios where material specifications and processing types are relatively simple.
A few years ago, the answer to choosing between a circular saw and a band saw was relatively simple. High-volume, high-volume applications may require the use of a circular saw, while if workpiece accuracy is not critical, an inexpensive band saw may be sufficient. But today, thanks to the development of band saw technology, the answer is not so clear-cut.
What is certain is that in some application scenarios, the circular sawing method is more economical and effective, especially for occasions with high requirements on machining accuracy and high efficiency. Although this equipment is expensive, circular sawing with carbide-tipped cold saw blades can significantly improve sawing efficiency.
However, in terms of current development trends, the application fields between these two sawing technologies have begun to cross each other. The disc can still provide high speed and high precision sawing; in the long run, the initial investment of the band saw is less, and it has more flexibility in sawing capacity, multi-layer sawing and bundle sawing, and currently A high-quality carbide band saw blade coupled with a band saw with good performance may also meet or exceed the workpiece accuracy and production efficiency indicators previously only achieved by circular saws. For example, in the sawing application of aluminum ingots, the current trend is to gradually replace circular sawing with high-speed band sawing.
1. The effect of material type and material specification on the two sawing methods
Start by asking yourself the following questions:
What is the diameter of the cut material?
Material type and grade ready for sawing?
Which material do you usually cut?
Is it sawing solid wood or pipe or both?
Will future projects change requirements?
Are you planning to offer other material models and specifications for new markets?
Generally speaking, circular saws cut diameters between 100 and 150mm. If the diameter exceeds 150mm, whether it is measured from the perspective of function or cost, it should be processed with a band saw machine.
Workpieces with diameters between 25 and 100 mm can be machined with either band saws or circular saws. Which method to choose depends on various influencing factors. In cold cutting, if the workpiece needs to be fast in and out, some common steels such as medium and low carbon steel, low alloy steel, tool steel, free-cutting stainless steel, and aluminum are more suitable for circular sawing, because these materials can Quickly cut by a circular saw without compromising machining quality due to excessive heat and friction causing premature edge wear. However, for difficult-to-cut materials such as nickel-based alloys and titanium alloys with low cutting efficiency, more heat and friction will be generated during cutting. A saw has 300~400 teeth, while a circular saw has only dozens of teeth to a hundred teeth), because each tooth tip has a longer “rest” time during operation, this processing method is more conducive to control The temperature of the tool, so difficult-to-machine materials of this size are more suitable for sawing with a band saw.
2. Analysis of current and future production needs
The following information is required for this:
How many cuts per hour, day, week or month?
Are these long term, productive, short term or occasional cuts? Will production demand shift to mass production in the future?
In any case, what is the size, material grade and quantity of the material to be sawed?
At present, the band sawing technology has developed advanced multi-layer sawing and bundle sawing functions, which can realize high-precision sawing processing of small-sized workpieces. With multi-layer sawing technology, band saws can rival the productivity of circular saws. On a standard circular saw, it only takes 10 seconds to cut a 50mm diameter Q235 round bar, but if you put five 50mm Q235 bars on a band saw, the band saw can also process it within 70 seconds After all, this cutting efficiency is almost the same as the efficiency of circular sawing machine processing, and it may also meet production needs. If the best band saw blade is used to set the band saw tension relatively high on a double column band saw machine with good rigidity and good stability, and the constant control technology of the cutting load per tooth is used for the sawing process, the workpiece tolerance and consistency will also be reduced. can be greatly improved.
Feed times can also be drastically reduced by sawing in multiple layers or bundles. If you are using bale sawing, seriously consider the fixture design. In fact, by using special fixtures, the circular saw can be cut in bundles, but it is limited to sawing workpieces with small diameters. As for cutting large diameter workpieces in bundles, the band saw is still the best choice. Bundle sawing of square or rectangular tubes may only require horizontal clamping, while bundling of round bar stock requires both vertical and horizontal clamping, which in some cases reduces sawing capacity because The fixture will take up some of the space in the work area, leaving less room for the material itself. Still, the best clamping method is to use both horizontal and vertical clamps to reduce vibration when sawing, as excessive vibration can greatly reduce tool life.
3. Analysis of the precision requirements of the workpiece to be processed
What are the tolerances for length, flatness and consistency of the final product?
Is secondary processing required?
What are the quality specifications for the finished product?
If the accuracy is improved, can the secondary processing be cancelled to save processing costs?
If the circular sawing machine uses a high-quality cold saw blade, the surface of the workpiece cut by the saw is very smooth, and the burrs on the edge of the workpiece will not exist. However, this is not necessarily a clear advantage over current band saw technology.
4. Analysis of cutting type
Does the material need to be corner cut or beveled? If so, what angle do you need to achieve?
What percentage of the workpiece needs to be chamfered and beveled?
Need to automate these processes?
If a large number of corner cuts are required, it is not feasible to do multi-layer or bunch sawing in a conventional horizontal band saw. At this point, the sawing efficiency of circular saws and band saws can be compared piece by piece. If the number of workpieces to be corner cut is limited, you can choose a horizontal angle miter band saw for small-gauge workpieces.
5. Long-term solutions
Try to look at current and future sawing needs. Management and procurement personnel may consider current expenses, while manufacturing and operations personnel may consider long-term machine productivity, both of which are important perspectives. Depending on the company’s current financial situation, consider whether it is important to control upfront purchase costs or whether the long-term financial return on the machine is more important.
If you compare the input and output of the fully automatic band sawing processing method with the fully automatic circular sawing processing method, generally speaking, the cost of the former is significantly lower than the latter. The scientific cost evaluation method is to use the cost calculation formula instead of simply comparing the equipment price. Do you need to consider whether to cut in a single piece or in a bundle? How many classes are there per day? What is the output per day? Is the circular saw blade reground? A large amount of empirical data shows that the cost per square meter of material sawed by a band saw is lower.