Tube Bending Services
Woolf Aircraft Products can bend a large variety of materials including but not limited to, Aluminum, Brass, Copper, Inconel, Chrome Moly, Copper Nickel, Carbon Steel, Titanium, and Stainless Steel tubes. Our machinery is capable of bending a range of outer diameters in sizes from 0.0625” up to 8” and everything in between to serve production volumes of any size (see our die list for bend tooling we have on hand). Tube bending is a collective term that describes a variety of forming processes that can permanently bend or change the shape of tubing or pipe. Tube bending capabilities are not universal to one machine. In order to produce a high-quality bend or multiple bends using various materials and various radii, Woolf Aircraft uses different types of bending apparatus. Each bending method is selected with the best fit of materials and dimensional attributes in mind.
What Is the Tube Bending Process?
The seasoned professionals at Woolf Aircraft set the standard for tube bending with the following three processes:
Rotary Draw Bending:
The Rotary Draw Bending process may be used to form single, multiple, or compound bends. Rotary Draw bending is performed with the use of a mandrel to assist in interior support throughout the bend. The mandrel to tube ID fit is within precise clearance measurement. With pressure being applied from within, it balances the outside forces more evenly. Having this balance allows for a thinner-walled material to be formed, in conjunction with the wiper die, we are able to produce a round, wrinkle free bend while maintaining a minimum wall thickness on the back of the bend. The maximum degree of the bend is generally 180° or less with standard tooling. Used in all of our bending departments including CNC bending.
Compression Bending is effective for straightening or single bend applications. The workpiece is clamped or held steady, and force is applied directly to create the bend. This method results in oval cross-sections and is generally limited to thin-walled or larger bend radii. Typically the bend is performed without internal support to balance the pressure, which can result in crushed bends. The maximum degree of the bend is generally less than 120°, though a 180° may be required for Serpentine Bends. This technique is used in the Small Bending Department and the Special Projects Cell.
Roll Bending is used for large radius bending. The tube is pushed through a set of three rollers to form a large arc. This set-up is not practical for small radius bends. It may take more than one pass to form within the dimensional tolerance. The resulting form has an unmarked interior, as there is no mandrel applied in the process. Maximum degree of the bend is 360°. Used in the Small Bending Department.
Which Materials Are Suitable for Tube Bending?
Various materials respond differently to bending, even when technicians use the same equipment and methodology. Because the process stretches materials to some degree, flexible metals usually work best.
Woolf Aircraft can bend the following types of metal tubing:
- Alloy 40 (21Cr-6Ni-9Mn Stainless Steel): Alloy steels are ideal for pipes in energy applications because they can withstand high temperatures.
- Aluminum: Aluminum is not as strong as steel, but is 1/3 of the weight, making it ideal for aerospace. Aluminum is a good conductor, and dissipates heat well. There are seven aluminum alloys with specific properties and purposes:
Series 1xxx: Corrosion resistant and easy to fabricate.
Series 2xxx: High machinability at elevated temperatures, but low resistance to corrosion.
Series 3xxx: Normally used in bending, with good corrosion resistance and machinability.
Series 4xxx: Low melting point, used primarily for welding.
Series 5xxx: High strength, corrosion resistance, formability, and weldability.
Series 6xxx: High strength, corrosion resistance, formability, and weldability, and able to be heat treated.
Series 7xxx: High strength, hard to bend.
- Brass: Brass is malleable, hard, and ideal for rolling, drawing, and bending projects. Brass is also a versatile material with varying characteristics depending on the copper and zinc content.
- Copper: Copper is easily formed, ductile, corrosion-resistant, and malleable. It is also one of the best conductors of electricity. As a result of copper tubing’s high conductivity and malleability, careful consideration must be put into the end-use, as thermal changes coupled with movement may cause fractures.
- Copper-Nickel: By adding nickel to copper, the newly formed alloy has improved strength and resistance to oxidation and corrosion. A 70/30 alloy is ideal for marine applications with exposure to seawater.
- Hastelloy: Hastelloy is a nickel- and cobalt-based alloy. It’s resistant to corrosion and easy to weld.
- Inconel: A superalloy, Inconel is designed to use in extreme temperatures. It’s a nickel- and chromium-based, which makes it resistant to corrosion.
- Stainless Steel: Stainless steel is popular because of its versatility. It can be used in interior and exterior applications and is water- and corrosion-resistant.
- Steel: Carbon Steels are predominantly a mixture of iron and carbon. The ratio of these two elements affects the hardness, strength, ductility, and ease of bend. The higher the carbon content, the more difficult the product will be to bend.
They are further classified below:
Low Carbon Steel – ≤ .3% Carbon
Medium Carbon Steel – .3 -.6% Carbon
High Carbon Steel – ≥ .6%
- Titanium: Titanium has a high strength to density ratio and is resistant to corrosion with a useful life span of 20-40 years. Used often in Navel and Aerospace applications.
What Finishing Options Are Available for Tube Bending?
After a tube has been shaped, the next step is to finish the ends to ensure the part fits securely into the system for which it was designed.
Woolf Aircraft offers the following finishing services to ensure the tube integrates flawlessly:
- Victaulic Grooving
Combining Tube Bending With Additional Services
Choosing one vendor for comprehensive tube bending projects ensures consistent quality control and tight production times.
Woolf Aircraft provides the following services alongside tube production and finishing to streamline your manufacturing process:
- Mechanical Assembly
- Part Marking
- T-Drill Pullout
- CNC Machining
Contact Woolf Aircraft for Tube Bending Services
At Woolf Aircraft, we specialize in high-quality tube bending services with superior strength and precision. Contact us online to learn more about our capabilities and in-house tooling for fixturing, or call (734) 721-5330 place an order today.