profile bending machine

Profile bending machine
Angle & Section Bending Machine
Manufacturer

FAQ

Description:

Section bending process is less costly than some and far more expensive than others, so its suitability depends largely on not only your application and productivity requirements, but also your budget.

Here is a glossary of common bending-rolling terms, taken from Design Guide 33.

1.What is Angle bending machine?

Angle Bending Machine is a kind of highly effective processing equipment which especially used in various of special sections, such as angle steel, channel steel, l-steel, flat steel, square steel, round steel and so on. Angle Bending Machine can complete the procedure of bending circle and corrective round working with one time load the material.
Angle Bending Machine are also referred to as Angle Roller, Section Bending Machine, Angle Rolling Equipment, Angle Rolling Machine, Angle Steel Bending Machine, Profile Bending Machine and Steel Angle Rolling Machine.

2.How to choose a Angle bending machine?

According to the material of your profile "Max.Section" and "Min.bending DIA".Reference Angle Bending Machine Technical Data.

You can also choose the required model according to the bending material:Square Bar (square steel), Round Bar, Flat Bar (flat steel), Equal Angle, Unequal Angle, Tees, channel steel, H & I Beams , Round Tube, Square Tube

3. What shipping methods do we offer?

In order to ensure safe shipping of our goods, we package the machines within a wooden box (except when a complete set of equipment is ordered) . Generally, we use Sea transportation for shipping.

4. I am an importer, can you supply the OEM service?

Yes, we can, please send me the details and we will assist you to place an order.

5. What are the five typical methods of bending?

Rolling (cold bending)

It is a typical method for bending steel for construction, and it is usually the most economical for rolling members with a small radius. The steel members were placed in the machine and bent between the three rolls. Cold bending can also be referred to as "pyramidal bending", which occurs when the distance between the rolls is manipulated before each successive pass.

Incremental bending

It is usually bent or bent to a large radius using incremental bending or plug bending. Bending is achieved by applying a point load with a hydraulic plunger or pressurizing at a third point of the member.

Hot bending

It refers to the position where the structural components are directly heated and then bent. The heat source can be a direct flame or a furnace. This application is widely used for repairs.

Rotary-draw bending

The member rotational stretch bending is a position where bending is performed by rotating the structural member around the mold. The part is clamped into a shape and then pulled through the machine until it is bent. This method produces a smaller radius and is primarily used for complex elbows in the mechanical and parts industries.

Induction bending

An electrical coil is used to heat a small length of structural member, and then the member is stretched by a process similar to rotational stretching and then directly cooled with water. In some cases, this process can produce smaller, smaller radii.

6.When we order a profile bending machine, shall we indicate if it will be installed in horizontal or vertical position?

No, all the section bending machines we produce can be installed both in horizontal and vertical position.

7.What Is the Difference Between Tube and Pipe?

Often today, you may not have actual part prints available to confirm material size and dimensions. A measuring device such as vernier calipers can be used to gauge the material’s outside diameter (O.D.) and inside diameter (I.D.), which will enable you to confirm necessary dimensions and make simple drawings.

Knowing the material’s true dimensions is key to selecting the proper machine and tooling for your application. Pipe sizes are measured by I.D., with wall thickness referred to in terms of schedule. Tube sizes are based on O.D., and wall thickness is referred to in gauge sizes.

For example, a 1-1/4-in. schedule 40 pipe has a 1-1/4-in. I.D., and a 1.66-in. O.D.;

whereas a 1-1/4-in. tube .65 wall has a 1-1/4-in. O.D. and a 1.120-in. I.D.

8.Why Is Material so Important?

When purchasing tube for your job, remember that the cheapest isn’t always the best. Bending tube or pipe of poor quality material often leads to poor-quality bends, higher rates of scrap, and possible breakage. Even the best machinery and tooling won’t overcome poor-quality tube material.

Material grade affects the tooling selection and composition; make sure the tooling is supplied to your material specifications so it doesn’t conflict with the material to be bent. As an example, stainless tube can conflict with a steel counter bend die.

When making a decision about material for your application, consider application strength requirements, appearance and quality, and centerline radius specifications. Ask your steel supplier for the material specification to ensure the material is appropriate for bending.

9.How do we order spare parts for our profile bending machine?

Please send us an email indicating the machine serial number, the spare part code and possibly send us also a picture of the spare required.

10.Can we bend bigger sections than the ones indicated in the capacity chart of the profile bending machine?

We recommend to work respecting the maximum capacity indicated in the capacity chart of the section bending machine and we will not take responsibility of damages caused by improper usage of the machine. Nevertheless is also possible, in some cases, to bend a bit bigger sections, especially if the bending radius is really big.

11.Can we bend to bigger diameters than the ones indicated in the capacity chart of the profile bending machine?

Yes, it is always possible to bend to bigger diameters than the ones indicated in the capacity chart of the section bending machine

12.Can we bend to smaller diameters than the one indicated in the capacity chart of the profile bending machine?

Power of the machine – In this case to bend to smaller diameters is necessary a machine with higher capacity

Diameter of the rolls – In this case is sufficient to modify the diameter of the standard rolls

Deformability and distortion of material – In this case is necessary the usage of special tooling or filling material, but there are some particular situations where a section bending machine is not the correct technical solution

13.To which material refers the capacity indicated in the capacity chart of the profile bending machine?

The capacity indicated in the capacity chart of the section bending machine refers to normal steel with yield strength 240 N/mm2

14.Is it always possible to bend the section to the minimum bending radius indicated in the capacity chart of the profile bending machine in a single passage or multiple passages can be required?

Normally the minimum diameter indicated in the capacity chart of the section bending machine can be achieved in multiple passages.

15.During the bending process using a profile bending machine is the surface of the material damaged?

Some scratches can appear on the surface of the material. In case of sensitive material the usage of special rolls is recommended.

Using a profile bending machine, is it possible to bend the full length of the profile?No, on all section bending machines, at both ends of the profile, a certain length remains straight.

16. What is the tolerance of the produced parts that can be achieved on your profile bending machines?

We always guarantee the tolerance in the positioning of the movable parts of the section bending machine. We prefer not to refer to the tolerance on the final result because that is strongly affected by the material properties, on which we don’t have a direct control.

17.Is it always possible to bend smaller profiles than the ones indicated in the capacity chart of the profile bending machine?

Theoretically yes, but for practical reasons the operating range of the section bending machine must not include profiles too small compared to the maximum capacity of the machine.

16.Can we bend to smaller diameters than the one indicated in the capacity chart of the profile bending machine?

Power of the machine – In this case to bend to smaller diameters is necessary a machine with higher capacity

Diameter of the rolls – In this case is sufficient to modify the diameter of the standard rolls

Deformability and distortion of material – In this case is necessary the usage of special tooling or filling material, but there are some particular situations where a section bending machine is not the correct technical solution

17.To which material refers the capacity indicated in the capacity chart of the profile bending machine?

The capacity indicated in the capacity chart of the section bending machine refers to normal steel with yield strength 240 N/mm2

18.Is it always possible to bend the section to the minimum bending radius indicated in the capacity chart of the profile bending machine in a single passage or multiple passages can be required?

Normally the minimum diameter indicated in the capacity chart of the section bending machine can be achieved in multiple passages.

19.During the bending process using a profile bending machine is the surface of the material damaged?

Some scratches can appear on the surface of the material. In case of sensitive material the usage of special rolls is recommended.

Using a profile bending machine, is it possible to bend the full length of the profile?No, on all section bending machines, at both ends of the profile, a certain length remains straight.

20.What is the tolerance of the produced parts that can be achieved on your profile bending machines?

We always guarantee the tolerance in the positioning of the movable parts of the section bending machine. We prefer not to refer to the tolerance on the final result because that is strongly affected by the material properties, on which we don’t have a direct control.

21.Is it always possible to bend smaller profiles than the ones indicated in the capacity chart of the profile bending machine?

Theoretically yes, but for practical reasons the operating range of the section bending machine must not include profiles too small compared to the maximum capacity of the machine.

21. What Is Rotary Draw Bending?

By definition, a rotary draw bend is formed by drawing the workpiece around a rotating bend former. The leading edge of the material to be bent is clamped to the bend forming die, while material rests between the forming die groove and the opposing force, commonly referred to as the counter bend or pressure die. The forming die rotates to desired degree of bend completing the process.

22. What Is Centerline Radius?

Often, centerline radius (CLR) is confused with the degree of bend. CLR is the distance from the center of the forming die to the centerline of the material to be bent. This distance often is overlooked, yet it is critical to achieving appropriate bend quality.

Factors that affect the CLR include the material grade to be bent, wall thickness, the type of bender to be used, the application, and overall appearance required. Generally speaking, CLR dimensions produce bends with better quality and appearance to the eye.

Bending materials to CLR less than two times the material diameter requires internal support of a mandrel to prevent the tube from collapsing. Rotary draw mandrel bending generally requires more expensive machinery and tooling than nonmandrel-style rotary draw machines. For this reason, be sure to review the application’s CLR carefully during the design stage, and consider the cost of manufacturing.

23.What Is the Maximum Degree of Bend?

This may sound simple; however, it is not if you are not given prints and are asked to reproduce parts from sample pieces.

Rotary draw bending tooling usually is designed to accept a maximum bend angle of 180 degrees. When selecting bending machinery for your application, be sure the machine program or system allows for slight overbending to compensate for springback during the bend cycle. Selecting a bending machine with a programmable bend angle setting can provide high bend accuracy and ease of use.

Degree of bend also affects bend quality. When working with a new material, try making two test bends—one at 45 degrees and one at 180 degrees. You may see slightly different results in the workpiece, because greater bend angles produce more wall thinning and deformation in the material.

24. What the Heck Is Springback?

After the bend cycle, all materials are prone to a springback affect. Essentially, material relaxes after the counterbend die pressure is released. Most materials are slightly overbent during the bend cycle to compensate for this effect.

Springback amounts vary depending on the strength and tensile of the material being bent. In addition, springback changes with the degree of bend and the CLR of the forming die.

Higher-quality bending machinery allows the operator to compensate for springback for each bend throughout the bend sequence.

25. Why Is Minimum Distance Between Bends a Factor?

Tooling for rotary bending requires a straight section of material for the forming tool to clamp the workpiece securely and prevent slippage during the bend cycle. Applications always should be reviewed for the shortest distance between any two bends, and the tooling should be manufactured to compensate for this distance if possible.

Less expensive bending machines might not allow the operator to achieve this distance, so the workpiece might need to be cut and welded after the bend to achieve the desired distance between bends.

26. How Many Bends Can I Produce?

Productivity requirements vary greatly, from job shop work to high-production runs. Actual bend cycle time often is insignificant relative to the overall cycle time.

To determine a realistic time, consider and allow for the following variables: operator experience, material loading and unloading, positioning time between bends, and machine speed and features, as well as secondary operations such as cutting, deburring, and welding. Be realistic about your productivity goals and select a bending machine with the appropriate duty cycle.

27. When designing with curved steel, when should an architect involve a bender-roller?

As early as possible and preferably during the preliminary design phase. Again, the earlier a bender-roller is involved in project design, the better. Providing as much information up front as you can will help clarify the design possibilities, decrease the number of requests for more information and control the costs. Sometimes, small changes in the size or member can significantly impact the project’s outcome.

28. Does curving steel affect its strength and integrity?

The curving process does not reduce the strength or structural integrity of the steel. When a shape has been curved successfully, the strains the member will experience under actual service conditions will be much smaller than those associated with the curving operation. Once the curving is done, the member can be expected to perform as needed.

29. Is curving steel a better option than creating the appearance of a curve with multiple segments?

As noted previously, it’s less costly to curve a length of material versus miter cutting and welding multiple segments to achieve the appearance of a curved assembly. In addition, a continuous curve facilitated by the bending process appears much smoother than a segmented assembly made from multiple sections. Bottom line, curved steel looks better than a “faked” curve.

30. What items will a bender-roller ask you for when you approach them with a curved steel project?

For starters:

• Your overall vision for what you want to bend

• Member shapes and sizes and material type to be bent

• How the members will be oriented

• Correct nomenclature to match what is drawn (i.e., “inside radius”)

• AESS requirements, if any, for the curved members


31. Diving deeper, what details should designers include on curved steel documentation for bender-rollers?

Since a curved member’s size and specified radius will determine how a bender-roller will approach the forming operation, and ultimately determine the process and machine used to form said member, it is extremely important to accurately convey as much detailed information as possible on curved members in the architectural and structural documents in order to get the most accurate cost for what is typically referred to as the “curved/formed metals package.”

Many construction projects if not all, release structural and architectural prints for the general contractors and subs to bid on. A vast majority of these prints containing rolled members do not contain the necessary details needed to accurately calculate the costs of producing formed members. A properly detailed print containing rolled members should always detail radius and arc length, along with the proper section views to determine the orientation that the member is rolled or formed. Many times, this lack of information has forced subcontractors to speculate on the curved member’s radius and/or to scale the rolled member from other members on the print and use that information to make a best guess at the radius. The result is that what was bid/quoted is not what was needed or intended to be conveyed by the design documents provided. This can cause major delays and cost increases for a project, especially when it happens mid-fabrication/erection.

32. What’s the best way to bend steel?

Several factors determine the best technique, including the overall member size, web and flange thickness or HSS wall thickness, radius requirement and end application of the material. Also, keep in mind that varying amounts of extra material are required at one or both ends of the member, depending on the process used; you don’t want to have to splice additional material to one or both ends. Talk to a bender-roller about the best options for your particular application as well as their capabilities. The various bending types and methods are discussed later in this article.

34. Does AISC impose any tolerances on curved beams?

There are limited tolerances for curved members in the AISC Code of Standard Practice for Steel Buildings and Bridges (ANSI/AISC 303, a free download at www.aisc.org/specifications.) According to Section 6.4.2, “For curved structural members, the variation from the theoretical curvature shall be equal to or less than the variation in sweep that is specified for an equivalent straight member of the same length in ASTM A6/A6M.” Other acceptable tolerances, such as any cross-sectional distortion, are not generally available because they are dependent on whether the member is AESS as well as any effect they may have on the member strength. AESS tolerances are discussed in Section 10 of the Code. The actual geometric imperfections for rolled members are dependent on several factors, including:

• Cross-sectional shape of the beam

• Bending radius

• Bending axis

• Bending method used by the bender-roller

• Equipment limitations of the bender-roller

It is best to discuss the required tolerances with the bender-roller who will provide the service—and be sure to add the required tolerances to the contract documents to ensure that you get what you are asking for.

35. What are some considerations for members with multiple curves?

Designing compound/multi-radial members allows architects to bring a “wow” factor into their design, but it also helps in eliminating connections (especially if the shrinkage/growth of curved members and the specified connections of those members is a consideration). It is important to understand and grasp the idea and principle of tangential arcs. When a design calls for a single member with adjacent arcs of differing radii—commonly referred to as a compound or multi-radial member—it is extremely important to design the arcs tangent to one another. If the arcs are not designed tangential to one another, then it is like having a miter cut at that point, or having to bend the member at that point with a press brake or a three-point gag press/ram bending machine.

36. The question arises: How do you know when arcs are tangential to one another?

The answer can be found in the detailing or dimensioning of the arcs. When arc dimensions are pulled on each of the radiused portions of the curved member, one can tell if the arcs are tangential by looking at the leader lines of the arc dimensions. If adjacent dimensions’ leader lines fall exactly over one another and cannot be distinguished from one arc to the next, then the adjacent arcs/lines are tangent. If the two leader lines of adjacent arcs form an angle and are completely distinguishable from one another, then the two arcs or radii in question are not tangent and, as described above, would either need to be pressed/kinked at that point in order to achieve the desired geometry or be miter cut and have a connection placed between the adjacent arcs. Designing with tangential arcs or radii simplifies the curving process and is necessary to achieve the desired geometry when using bending-rolling methods without pressing or kinking.

37. Is it possible to put a 90° bend in a pipe?

Yes. The key factors are the radius and the bending method used.You will need to contact a bender-roller or a fabricator to discuss the limits, options and costs.

38. When are reverse curves necessary?

It is sometimes necessary to design reverse curves with a small amount of straight or tangent in between opposing radii. This is due to the necessary bending moment needed to induce the second curve, which is required due to machine limitations. Most members can be redesigned to achieve this mid-tangent. In some cases, and with special machinery, it is possible to eliminate or drastically reduce the straight needed in between opposing curves.

39. What is the maximum geometric camber that I can specify for, say, a W27 rolled beam?

The capabilities of bender-rollers and fabricators vary, as do the equipment used and the cost. A tighter radius can often be obtained using a more sophisticated and costly process. It is best to speak with a bender-roller and a fabricator to get their opinions.

40. Is there a minimum radius for bending?

Minimum radius is merely a concept. Each bender-roller has their own practices, machinery and developed technologies that, when applied to specific rolling jobs, can produce very different results.

41. How do you address cross-sectional distortion with curved members?

Regardless of whether you can eliminate wrinkles and/or concavity (which is the most common type of undesirable distortion) shrinkage and growth can severely limit the ability to make connections and can cause major delays and have cost implications to a project. Welded connections, especially full-penetration, require a very good fit-up in order to achieve the desired results. Cross-sectional distortion in the form of shrinkage and or growth can drastically limit the ability of the fabricator to make welded connections. When a curved member is to be connected to a straight member or if two curved members of differing radii are to be connected with a welded joint, it is always best to keep in mind the possibilities of cross-sectional distortion and how that may negatively affect the fabricator’s ability to make a connection. Bender-rollers do their best to limit this type of distortion, which is often referred to as shrinkage and or growth (some companies have established “up to and including 5%” as in-house tolerances) but seeing that there is not an established AISC tolerance on the amount of acceptable cross-sectional distortion of a curved member, it is always best for architects to design with this in mind.

We have compiled some knowledge about the bending of the profile, here is its link on our website:
https://www.profilebendingmachines.com/section_bending.htm

About Us

Nantong Borisbang Industrial Technology (NBIT) rooted in Haian County of Jiangsu Province,China. The main production section bending machine. NBIT was founded in 2001 and has more than 17 years experience in this field.

Nantong Borisbang Industrial Technology (NBIT) is your specialist and technology partner for powerful and future-proof bending machines and bending solutions.Having a solid trained technical team with a wide range of quality Section Bending Machines, and On-Time Deliveries, we have been accumulating happy customers worldwide.

Our core focus and specialisation is in the Section Bending Machines.

Over the years, the Company has grown multifold and currently exports to several countries in Sweden, Germany, England, Thailand, Iran, Korea, Vietnam, Russia, Malaysia, Dubai, Saudi, Arabia, India, South Africa, United Arab Emirates, Singapore, Uzbekistan.