Steel grade saws for metal band
Main operating parameters
The choice of a band saw should be based on the characteristics of the main production, as well as its power capabilities. For example, the Jet metal band saw is one of the best in terms of price-performance ratio.
It should be remembered that using this type of blade, you can cut almost all types of metal, as well as some other materials with your own hands.
Before starting work, it is necessary to check the tension of the blade, as well as its sharpness.
If necessary, the tool should be sharpened, and only after that the necessary tension is carried out directly on the equipment itself.
When choosing a band saw, price should not be the determining factor. Also, do not expect that the higher the price, the better the quality of the tool.
You need to focus on the average. The performance of this tool is of great importance.
In the event that a band-type saw will be used in a small production, it is recommended to make a choice in favor of universal devices, the price of which is within acceptable limits.
In large industries, it is better to use more functional models of band saws, although their price will increase slightly.
Also pay attention to the cutting material.
In the case when a cutting saw is required for processing simple types of structures, then you should choose from less functional devices, the price of which is within acceptable limits.
In addition, they are great for working with a wide variety of materials.
If it is necessary to regularly carry out work on the processing of complex material, it is recommended to choose a specialized saw.
You can opt for products with increased tooth rigidity or diamond-coated.
Of course, the price of such a band saw will be slightly higher, but it should be borne in mind that the quality of work and the service life of the tool will increase several times.
One of the main indicators for tape-type slabs is the tooth pitch. In many ways, not only the service life of the tool itself, but also the quality of the work performed depends on the tooth pitch.
In this case, it should be borne in mind that the higher the thickness of the workpiece, the smaller the step should be and vice versa.
It is also necessary to pay attention to how the tool is sharpened. How to work correctly on a band saw is described in the video posted above.
In most cases, band saws are used to cut all kinds of metal rods, pipes, as well as fittings.
They perform straight as well as oblique cuts in the workpiece material.
The main cutting tool in saws of this type are blades, which are characterized by tooth stiffness, and in addition, the ability to work on a particular metal and productivity.
Converting Delta Saw to Metal Cutting #488 p1 pull gear tubalcain
There are other parameters of the band saw blade operation that you need to know in order to choose the right tool.
So, among the leaders of the domestic market for this type of equipment, there is a great demand for products under the Corvette brand.
The price of Corvette saws is within affordable limits and fully corresponds to their quality. In addition, some craftsmen assemble fairly productive band saws with their own hands.
Cutting surfaces with band-type saws is quite simple, and there is no need to have special qualifications to work on equipment of this class.
Cutting metal products using band saws has a number of advantages when compared with the use of a similar tool.
First of all, it should be noted that band-type saws give a clear and accurate cut at the output, which practically does not need further processing or grinding.
This allows not only to save working time, but also to reduce the cost of purchasing additional tools.
It should also be noted that such manual cutting of metals is characterized by high productivity, moreover, the service life of the blade itself is quite long.
When working with a band saw, a minimum amount of production waste is generated in the form of metal shavings.
In general, a band-type saw is a fairly versatile tool in its class for DIY work. Many other materials such as plastic and wood are easily cut with it.
It is easy to work on such equipment even with your own hands. The video that is posted above shows in detail the process of working on a band saw.
In order for it to be convenient to work on the saw with your own hands, it is necessary to select the technical parameters of the blade as accurately as possible.
The cut-off band saw is also characterized by parameters such as feed and speed.
You should set the required tension with your own hands, guided by the design features of the tool.
The free wheeling of the saw ensures the correct tension, as well as the setting, which can be of several different types.
So, for steel, as well as non-ferrous metals, cutting is done with a standard wiring.
Cutting profiles, pipes, as well as other parts with a variable cross-section is carried out with variable wiring.
In turn, cutting thin products with a small diameter is carried out by wave routing. When choosing a blade, one should also be guided by the shape of the tooth, which can be of different types.
It should also be remembered that the sharpening of this tool with your own hands is carried out in a special way according to a certain technology.
There are many other nuances that are individual in nature, in relation to the type of equipment used.
Manufacturers currently offer a large selection of band saws that have different characteristics of their work.
Equipment under the Corvette brand has proven itself well. Corvette offers a wide range of band saws for various purposes.
When using the Corvette band saw, the cut is smooth and straight.
Corvette equipment is characterized by high performance and reliability, as well as high technical parameters, which ensure high quality of the work performed at the output.
Some models of saws under the Corvette brand are equipped with a rotary vise that makes it easier to do the corresponding work with your own hands.
The Jet metal band saw also performs well.
This tool is designed to work with various types of materials and is characterized by high performance and optimal reliability.
In the video above, you can see the Corvette band saw in operation.
How to choose a band saw for metal?
Currently [metal band saws] are one of the most important blank production devices. From the article you will learn how to choose the right tool, as well as understand why timely sharpening of the tool, the brand of the manufacturer and the cost when choosing a saw are so important.
Due to their variety and the most optimal cutting modes, such saws provide not only the highest productivity, but also several times reduce the cost of this type of processing.
The main element of this category of saws are blades, which are made mainly of high quality carbon steel.
Such blades allow you to successfully work with both alloyed and non-alloyed metal alloys. To choose a saw, you need to decide in advance which type of blade is more comfortable to work with.
At its core, the band saw is the main working body of the band saw equipment.
The blades used in this process are a closed circuit with sharpened teeth of the correct shape.
These versatile cutting devices for various types of materials are widely used in a wide variety of industrial applications.
They can be found at various construction sites. Band saws are a must-have for the aeronautical and automotive industries.
In addition, they are also used in small production halls to solve a wide variety of tasks.
The vertical cutting band saw is currently represented in the relevant market in a large assortment.
In order to choose the right tool, you need to accurately represent its main purpose.
Tips & Tricks
Sharpening of band saws should be done using special equipment.
For this, a special machine is used, which makes it possible to do the necessary work with your own hands as soon as possible.
How to sharpen band saws with your own hands is described in detail in the video, which is posted below.
It should be remembered that when working with a saw, safety rules must be followed. Carefully adjust the tool and control the blade tension. Optimal sharpening of the tool also plays an important role, it is thanks to it that manual work on the Corvette saw is so comfortable and enjoyable.
There is such a concept as the rest of the canvas, which characterizes the fatigue of the material during intensive work. If long-term work on the saw is planned, then it is recommended to use two hotel blades.
When choosing a saw, it is recommended to pay attention not only to its cost, but also to all technical characteristics, as well as to the name of the manufacturer. It should be remembered that manual work with a band saw for metal with your own hands should be comfortable. Naturally, the price of the tool affects the capabilities of the tool, but it should not become the main criterion for choosing a saw.
The material from which the canvas is made is also of great importance. The video below shows the Jet saw in action.
Description GOST R 53924-2010
GOST R 53924-2010 was prepared by JSC VNIIINSTRUMENT, introduced by the Technical Committee for Standardization TK 95 “Instrument”, approved and put into effect by Order of the Federal Agency for Technical Regulation and Metrology dated November 12, 2010 N 399-st. GOST applies to endless band saws for cutting section and shaped rolled metal, castings, sheet material, pipes and other products made of ferrous and non-ferrous metals, as well as non-metallic materials on band saw machines.
GOST R 53924-2010 includes modified basic regulatory provisions of the following international standards:
– ISO 4875-1: 2006, “Metal-cutting band saw blades. Part 1: Vocabulary”;
– ISO 4875-2: 2006 “Metal-cutting band saw blades. Part 2: Characteristics and dimensions”.
The following standards are used in this standard:
GOST 3882-74 Hard sintered alloys. Grades (ISO 513-75 “Hard tool materials for cutting. Designation of the main groups of chip removal and groups of application”, MOD).
GOST 5950-2000 Bars, strips and coils from tool alloy steel. General specifications.
GOST 19265-73 Bars and strips from high speed steel. Specifications.
Options for the manufacture of tape canvases:
blades made of tool alloy steel in accordance with GOST 5950;
2. bimetallic blades (cutting part material. high-speed steel according to GOST 19265);
3. blades made of tool alloy steel with teeth equipped with hard alloy in accordance with GOST 3882;
4. friction cutting blades (under the influence of frictional heating) made of steel resistant to fatigue.
Types of tooth setting:
Standard set: Transverse set of each tooth alternately right and left.
Note. does not apply to canvases intended for work on ferrous metals.
Figure. Setting two adjacent teeth through one undistributed.
Setting two adjacent teeth through one unset: Setting one tooth to the right, one to the left, one without setting.
Figure. Setting two adjacent teeth through one undistributed
Wavy set: Transverse set of groups of teeth with regular change of direction of the set to the right and left.
Figure. Wavy layout
Group setting: Transverse setting of several teeth alternately to the right and left, followed by one at least undisturbed.
Figure. Group wiring
The general setting of the teeth of band saws of all versions. at the discretion of the manufacturer.
The setting of the teeth on the sides of the blade should be equal.
Limit deviations of the wiring. ± 0.05 mm.
The straightness tolerance of the lateral sides of the web in the transverse direction over the entire width of the undivided part should be no more than 2 μm / mm.
The main dimensions of the canvases must correspond to those indicated in the table
The length of endless band saws is determined according to the type of machine used.
Band saw steel grade for metal
There are the following types of materials from which Wikus band saws are made:
Let’s consider them in more detail.
Tool steel band saws
These band saws are manufactured from a solid strip of high quality alloy and hardened carbon tool steel. A hardened cutting edge and an extremely flexible backing strip guarantee the high quality of these blades. The hardness of the cutting edges of the teeth reaches 65-67 HRC.
Such saws are mainly used for sawing simple materials: unalloyed steels with low tensile strength, for cutting composite materials, for friction sawing on special machines. They are most suitable for use in the repair shop environment.
The production program and scope of each of the canvases can be viewed at the link.
Bimetal Band Saw Blades
The base blade of such a band saw is made of elastic spring steel (analogue. 45HGNMFA). A high-speed steel (HSS) profile wire is welded to the base blade by electron beam welding, after which the sawtooth profile is milled.
After the subsequent heat treatment, the cutting edges of the saw teeth have a hardness of 67.5. 69 HRC, and also have the outstanding wear resistance and redness characteristic of high-speed steels. This makes it possible to successfully use bimetallic saws in processing up to 90% of steels and alloys used in industry.
Depending on the brand and composition of high-speed steel, bimetallic saws of almost all manufacturers are divided into 2 main types. M42 and M51.
For bimetallic band saws from Wikus:
Hardness of cutting edges of teeth 67.5-68.5 HRC.
This material is suitable for sawing all major steel grades with hardness up to 40-45 HRC.
This allows this tool to be used for cutting high-strength, stainless and heat-resistant steels, including workpieces with a large cross-section and hardness up to 45 HRC.
Cutting edge hardness 69 HRC.
The durability of such a band blade, as a rule, is 10-20% higher than that of saws with a cutting edge material made of M42.
In 2009, Wikus discontinued saws with M51 cutting edge material and introduced a new generation of high-tech material. X3000. This material occupies a special position because it is obtained from high-quality high-speed steel by powder metallurgy. This made it possible, in contrast to traditional high-speed steels (M42 and M51), to achieve the following advantages:
Get a fine-grained structure with a more even distribution of dispersed carbides.
2. Significantly increase the hardness (up to 69-70 HRC), wear resistance and heat resistance, while maintaining the technological plasticity of the material.
3. To increase the reliability of the tool due to a decrease in the likelihood of the formation of defects during cutting, such as burns, chips and microcracks.
4. Increase tool life up to 25-50%.
Sawing austenitic, stainless, acid-resistant and other exotic steels and alloys is no longer a big problem thanks to the combination of the new high-performance cutting edge material X3000 and the optimized geometry of the GIGANT and VECTOR bi-metal band saws.
The production program and scope of each of the canvases can be viewed at the link.
Carbide Band Saw Blades
This tool is recommended for high-performance cutting of exotic, difficult-to-cut, heat-resistant and stainless steels and alloys, titanium, nickel, etc. hardness up to 62 HRC. Specially ground tooth geometries with cutting edge hardness up to 1600-3800 HV make the Wikus carbide saw program suitable for the most demanding needs.
These saws are of two types:
The production program and scope of each of the canvases can be viewed at the link.
Diamond band saws
Since diamond is the hardest material in nature (hardness up to 9000 HV), it is able to cut almost any material, metal and alloy. These are aluminum with inclusions of solid particles, and hardened and chrome-plated shafts, hard alloys, ferrodo, tempered glass, marble, granite, quartz, graphite, etc.
Bandsaw equipment is one of the main components of metalworking production and the manufacture of metal structures, one of the fastest, most accurate and economical ways to cut a significant amount of rolled solid and variable cross-section. An important role in this is played by the characteristics of the band saw, its pitch, setting, durability, and other parameters.
The main types of band saws used in modern production are saws from carbon steel grades and bimetallic products, saws with a base made of ordinary steels with high resilience and cutting parts made of other grades of steels. hard or high-speed.
Benefits of sawing with band saws
Sawing technology on band saws is increasingly in demand in modern industries. The main advantages of using tape canvases include:
- the smallest amount of chips and waste from cutting;
- high precision manufacturing of the ends of parts;
- perfectly flat cut surface of the part;
- excellent performance and speed of the equipment;
- low noise and no vibration.
By using band saw blades instead of the basic cutting methods with discs and knives, in the end we get the opportunity to save money. Metal is consumed more prudently, the degree of production waste generation is significantly reduced. In addition, the quality of the manufactured products significantly exceeds the analogs of disk or cutting on a hacksaw machine.
Cutting modes and durability
A high-quality cut and the duration of the saw operation also depend on the optimal selection of the cutting mode. speed and feed. The mode depends on the material of the workpiece, its size and profile. The speed is adjusted according to manufacturers’ tables and on the basis of practical indicators of chip type and thickness. With thin, the feed increases or decreases the speed, with thick chips or blue tint, the feed speed decreases or the cutting speed increases. The best option is slightly curling shavings.
As for the durability of saws, it depends on the resistance of the material to wear and many other factors, including resistance to cyclic alternating loads and correct operation. As a rule, the canvases of the leading manufacturers are designed for 140. 160 hours of operation. This indicator can be increased by removing the canvases for relaxation and, of course, by the correct selection of cutting parameters.
Bimetal. the cutting part of the blade, which is laser-soldered to the base made of spring steel, is a complex alloy of several metals obtained in various ways. Bimetal HSS M42 (analogue of 10P2M10K8) and HSS M51 (analogue of 12P10M4K10) can be manufactured by the method of mutual simultaneous casting, synchronous pressing or electroplating. In the case of band saws for metal, different manufacturers use excellent methods for their manufacture, the quality of the blade, its strength and service life depend on this.
Recommendations for the operation of tape blades
Preparation for work. running in the band:
This is a very important point, since the resource of the belt mainly depends on the controlled “running-in” procedure. A sharpened pencil will break immediately, unlike a sharp, but slightly dull, the same principle when preparing a canvas. First, you need to let the blade run in to the machine pulleys, driving it idle through the air for about five minutes. Then, at a lower blade rotation speed, about 70% of the recommended and 50% of the recommended feed speed, cut the workpieces for about fifteen minutes, and only then bring the speed of rotation and feed to normal.
2. Blade tension:
The degree of tension of the band is indicated in the operating instructions for the machine. Professional and industrial models of bandsaw machines are equipped with built-in strain gauges, with which you can control the degree of tension. It is important not to overtighten the web, since due to the constriction, the durability is significantly reduced, which leads to the rupture of the tape web along the weld or the resulting cracks. If the blade is not tensioned enough, there will be a deviation from the perpendicular cutting plane and a twisted cut.
3. Operation of the blade:
The main indicator of the correct choice of cutting conditions is the absence of strong vibrations during cutting and the type of chips. Optimum cutting requires each tooth of the band to cut a certain chip thickness. In practice, the feed is selected according to the recommendations of the equipment manufacturers or according to the type of chips that are obtained during cutting. For thin or dusty chips, increase the blade feed speed or decrease the cutting speed. Lightly curling chips indicate the correct cutting mode. Thick or blue chips indicate excessive feed rate or less than necessary cutting speed. It is also important not to overheat the cutting material of the blade, hence it follows that intensive watering of the blade with coolant, the cutting zone and the workpiece being sawn is required. Reduce the feed if vibrations occur. Monitor the quality of the cut surface, seizure marks and cavities may be the result of incorrect selection of the pitch, processing modes or blade wear.
4. Rest of the canvas:
Resting the blade allows you to redistribute the fatigue stresses arising in the process of work, preserve the properties of the tool material and increase the service life. When working intensively throughout the working day, it is better to work with two canvases, one before lunch, the other after. At the end of the working day, it is imperative to loosen the tension of the blade, and even better, remove the blade from the machine, and, turning it inside out, hang it on a hook.
5. Approximate resource of tape blades:
The durability of the band depends on many factors, including:
– type of machine;
– operating modes;
– processed material;
– cross section of the material;
– canvas material;
– preparation of the canvas;
– observance of operating rules;
– finally, the mood of the worker.
On average, with a correctly selected tooth pitch, the resource of one running meter of the blade is enough to cut 1.5-2.5 m² of solid ferrous metal.
For sawing thin-walled workpieces, such as pipes, sheet metal and the like, belt blades with a fine tooth pitch are required, otherwise there is a risk of damaging or breaking the tooth of the bimetallic blade.
Large workpieces should be cut with coarse-pitch band blades. Coarse pitch increases productivity and leaves plenty of room for free chip formation.
Sawing soft and tough materials such as aluminum and bronze requires a lot of free space for the formation of chips, they also use large-toothed blades here, as they prevent the chips from accumulating and getting stuck between the teeth.
Main characteristics of band saws
Obtaining a high-quality cut and the duration of the product’s operation depend on the accuracy of the selection of parameters such as pitch, setting and tooth shape. An important characteristic of a saw band is the tooth pitch, which is the number of saw teeth per inch (TPI). The tooth pitch can be constant or variable. Constant is used when working with solid section workpieces in industrial volumes, variable provides minimal vibration and high cut cleanliness.
For products with a constant step, its value ranges from 1 to 32, with a variable step. 10/14. 0.75 / 1.25. Below are tables of recommended saw pitch sizes for cutting solid steel:
And the recommended step sizes for working with profile and pipes:
However, saw manufacturers often offer their own recommendations for working with solid workpieces, profiles and pipes. They should be guided by the selection of saws for solving certain problems.
The next important parameter is the angle of rotation or inclination of the tooth relative to the plane of the blade or, in a more simplified name, the setting. The free movement of the blade, vibration, noise, section of workpieces and the ability to work with thin materials depend on this. There are the following basic options for tilting the teeth:
- Standard is a left tilted tooth, followed by a right tilted tooth and a straight tooth. The most commonly used set-up for cutting workpieces of all steel grades.
- Variable. left, right and wiping teeth. Provides minimal noise and vibration, suitable for working with soft materials.
- Wave routing. for cutting thin-walled rolled products.
- Combined. for pipes, profiles with variable cross-section and packages.
The capabilities of the band saw blade for metal also depend on the shape of the tooth. There are the following basic forms:
- NORMAL (N) with 0 ° rake angle. Designed to work with high-carbon alloys, for thin sections and rolled products with variable cross-section.
- HOOK (H) with 10 ° rake angle. for thick-walled pipes and solid billets.
- RP with 16 ° rake angle. work with solid and extra hard solid workpieces.
- MASTER. angle 10 ° and 16 °, the presence of a ground chamfer located in the longitudinal direction.
Types of band saws
All modern blades for a band saw machine for metal, depending on the material, can be conditionally divided into three main categories:
- Saw blades made of carbon tool steel grades. A widely used type of band saws for economical cutting of many grades of steel, both unalloyed and alloyed. The tensile strength of this type of saws reaches 80 kPa / mm2.
- Bimetallic blades for a band saw machine for metal with a working part made of high-speed steel. have higher operating rates than products made of a homogeneous material. The most commonly used high-speed steel grade M42 (11P2M10K8) with additions of cobalt and molybdenum providing hardness up to 950 HV and red hardness. The tooth is connected to the spring part of the saw by electron beam welding.
- Carbide tooth bimetal saws. They are used under severe cutting conditions, for working with cast iron and other particularly hard materials. Used for cutting solid workpieces with a diameter of over 60 mm.
Marking and designation of tape blades
An example of decoding from the marking applied to the tape fabric Honsberg BI / M42 S 20×0.9×2362 mm, 10 / 14TPI:
Honsberg. German manufacturer of tape saws;
BI / M42. material of the cutting part of the teeth is bimetal M42;
S. Spectra tooth profile with 0 ° rake angle;
20. web width in mm;
0.9. blade thickness in mm;
2362. the length of the “endless” fabric welded into a ring in mm;
10/14. variable pitch of teeth, indicates that there will be 10 teeth on the first inch of the band, and 14 teeth on the second, which will subsequently alternate along the entire length every 2.54 centimeters (Inch = 2.54 cm);
TPI is an abbreviation for Teeth Per Inch, which translates to Teeth Per Inch.
Constant band tooth pitch. all teeth are the same and spaced at the same distance.
Variable tooth pitch of the belt. “small” and “large” teeth alternate every inch and it turns out that one inch has one constant tooth pitch, the second. another. Belt blades with a variable tooth pitch are most preferable when cutting metal, since they have a wider working range compared to a constant pitch, and also reduce vibration and noise of the band blade.
The difference between the tape blades M42 and M51.
The cutting edge of the M51 blade is slightly harder than that of the M42 blade, but also more fragile. Due to its fragility, it makes sense to use M51 blades when cutting solid workpieces that are not prone to vibrations, for example, it is perfect for sawing stainless steel round timber, which will not be able to cut the M42 blade. The durability of the M51 band blade is usually 10-20% higher than that of saws with M42 cutting edge material. Another important point, M51 blades cannot be less than 27 mm wide, and the finest tooth pitch will be 4/6 TPI (the first inch is 4 teeth, the second inch is 6 teeth). For comparison, for M42 belt blades and 27 mm wide, the finest tooth pitch can be 14 TPI (14 pieces per inch).
Jet HVBS-712K 414459T
Unlike the above-described machine for metal, this semi-professional one works from a power supply of 380 V. It has a hydraulic feed system and an automatic cut-off switch. Thanks to the powerful motor, this machine can withstand heavy loads and is able to work for a long time. Quick-clamping and firmly holding vise rotates up to 45 degrees. The set includes a wire brush for cleaning the workplace from shavings.
Stalex BS-260G 388017
This powerful band saw easily handles thick metal, therefore it is massively used in industries and factories. The machine is easy to operate and provides high cutting accuracy. It has two belt speeds and a pump for supplying coolant. For increased stability, its support legs can be attached to the floor. For convenience, there is a scale for adjusting the cutting angle.
The cheap model hit the top thanks to its high-quality assembly from reliable components. It works with different types of materials, including metals, has a rotary vise and a cut length limiter. The belt drive protects the engine from overload, extending its service life. For convenience, it has an additional desk. Vibration and noise during operation are practically not felt.
Selection and operation of equipment
When choosing a band saw for metal, you need to consider these factors:
- Saw thickness. it should be between 0.9 and 1.1 mm. The smaller the thickness, the lower the feed should be. The standard thickness is 1 mm.
- The width of the saw is from 14 to 80 mm, most often blades with a width of 31-41 mm are used. Wide band saws handle thicker metal more easily.
- Tooth pitch is the distance between sharp edges of adjacent teeth. The shorter the distance, the more precious the work. A long distance is suitable for working with hard metals, in which case a low speed is used. When regrinding, it is necessary to ensure that the step remains the same.
- Tooth shape. the best shape is considered if the rake angle of the tooth has 10 degrees, the clearance angle and the height of the tooth have little effect on the result.
- Number of teeth. the more teeth, the smoother the cut of thick-walled metal workpieces.
- Notch size. large teeth are chosen for deep cuts, medium ones for curly cuts, small ones for thin metal sheets.
General rules for the operation of equipment:
- Ensure that the teeth are always sharpened and correctly set.
- Do not work on a faulty machine, otherwise the result will be ruined.
- There must be sufficient light in the work area.
- Follow the shape of the grinding wheel.
- Thanks to individual adjustment, you can achieve impressive results from a conventional machine.
Top 10 best models
The top of the best models includes both floor and table band saws. If the former are massively used in production, the latter are purchased for households or private workshops. The best metal band saws have a powerful motor and can handle hard metal with ease.
Jet MBS-56CS 50000320M
This model of band saw is considered reliable for medium-sized production, and produces cuts at three different speeds. The robust design minimizes vibration, allowing precise and accurate work. Replacing the belt is quick and easy, no additional tools required. The machine is equipped with automatic engine shut-off and hydraulic feed system. Transportation is carried out using the wheels of the machine.
Resilience and speed
The durability of the saw band depends on:
- Correct cutting mode.
- The qualities of the tape.
- Saw designs.
- Body material and shape.
- Quality of cutting fluid.
If the machine suddenly vibrates, then you need to change the feed rate in the right direction. The duller the teeth of the belt, the higher the feed should be.