Small-Radius Bending of Aluminum Profiles

Small-radius bending of aluminum profiles is a highly difficult technique in the bending process. Conventional bending usually has a minimum radius of ≥500mm, whereas small-radius bending requires forming bends at extremely small radii of R100mm-R300mm, imposing very high demands on equipment accuracy, mold design and process control. The smaller the radius, the greater the tensile stress on the outer side and the compressive stress on the inner side of the profile, making outer cracking and inner wrinkling very likely.

Shanghai Chuangsi Aluminum Co., Ltd. provides a full-process one-stop service from extrusion and bending to CNC machining and surface treatment, equipped with high-precision CNC bending equipment, with a bending error of ±0.3mm, flatness of 0.1mm-0.3mm, applicable wall thickness of 0.8mm-3mm, and fit for round tubes, square tubes, channel aluminum and special-shaped profiles.

01 Quality Starts with Raw Materials

Produced from A00 primary aluminum ingot with no scrap aluminum; the material is uniform and elongation is stable. For small-radius bending, 6063-T5 with good elongation is selected to reduce cracking risk. If the customer specifies 6061-T6, the minimum radius must be ≥1.5 times the wall thickness.

02 High-Precision CNC Bending

By precisely controlling bending speed and feed rate, the bending error is ±0.3mm, flatness is 0.1mm-0.3mm, roundness is precisely controlled and the arc is uniform. Trial bending is verified before batch processing to confirm no cracking or wrinkling before mass production.

03 Dedicated Molds and Process Control

Small-radius bending requires custom dedicated bending molds that support the profile from the inside during bending, preventing cross-section deformation and collapse. Bending speed is also precisely controlled to avoid outer cracking or inner wrinkling caused by excessive speed.

04 Aging Stress-Relief Treatment

After small-radius bending, the profile carries significant internal residual stress; a matching aging stress-relief process releases the internal stress so that long-term running does not easily deform and the dimensional stability of bent parts is ensured.

05 One-Stop Delivery Service

Full-process one-stop delivery from extrusion and bending to CNC machining and surface treatment, so the customer only deals with one supplier.

Small-radius bending vs. conventional bending:

Comparison Item	Conventional Bending	Small-Radius Bending
Bending Radius	≥500mm	R100mm-R300mm
Cracking Risk	Low	Very high, requires strict control
Wrinkling Risk	Low	Very high, requires process intervention
Equipment Requirements	Ordinary bending machine	High-precision CNC bending machine
Mold Requirements	General-purpose molds	Dedicated molds
Process Requirements	Conventional roll bending	Precise speed control + dedicated support

Machining capability parameters:

Item	Parameter / Description
Minimum Bending Radius	R100mm
Applicable Radius Range	R100mm-R300mm
Applicable Wall Thickness	0.8mm-3mm
Available Materials	6063-T5 (recommended), 6061-T6 (requires evaluation)
Available Cross-Sections	Round tube, square tube, channel aluminum, special-shaped profile
Bending Error	±0.3mm
Flatness	0.1mm-0.3mm
Processing Equipment	High-precision CNC bending machine, roll bending machine
Supporting Processing	Extrusion, mold development, CNC machining
Surface Treatment	Anodizing, hard anodizing
Executive Standard	GB/T 6892-2023, ISO9001
Production Location	Qingpu, Shanghai

Key technical points for small-radius bending:

• Select 6063-T5 with good elongation to reduce cracking risk

• Custom dedicated bending molds to prevent cross-section deformation and collapse

• Precisely control bending speed to avoid outer cracking and inner wrinkling

• Apply aging stress-relief to release internal stress and ensure dimensional stability

• Verify by trial bending before batch production, confirming no cracking or wrinkling

Typical Application Scenarios:

• Small-radius bent structural parts

• Curved frames for compact spaces

• Curved equipment frames

• Precision bent structural parts

• Parts with special-radius bending

FAQ (Frequently Asked Questions)

Q1: What is the difference between small-radius bending and conventional bending?

A: Conventional bending usually has a minimum radius of ≥500mm and a relatively simple process. Small-radius bending requires forming bends at extremely small radii of R100mm-R300mm; the smaller the radius, the greater the tensile stress on the outer side and the compressive stress on the inner side, making outer cracking and inner wrinkling very likely. Small-radius bending imposes very high demands on equipment accuracy, mold design and process control and is a highly difficult technique. Our company uses high-precision CNC bending equipment, dedicated molds and aging stress-relief to effectively solve the challenges of small-radius bending.

Q2: What is the minimum radius achievable for small-radius bending?

A: The minimum bending radius is R100mm. The specific minimum radius depends on the profile cross-section size, wall thickness and material — the minimum radius is relatively small for round and square tubes, and larger for special-shaped profiles. We recommend that the customer provide the profile cross-section drawings and radius requirements so our company can evaluate whether small-radius bending is feasible.

Q3: How to choose between 6063-T5 and 6061-T6 for small-radius bending?

A: For small-radius bending, 6063-T5 is recommended first for its good elongation and excellent formability, which can effectively reduce cracking risk. If the customer specifies 6061-T6 (higher strength), the minimum bending radius should be appropriately increased (recommended ≥1.5 times the wall thickness). Our company can evaluate processing feasibility according to the customer's material and radius requirements.

Q4: How is outer cracking prevented during small-radius bending?

A: During small-radius bending, the outer side of the profile is under tensile stress; the smaller the radius, the greater the tensile strain, and the more likely it exceeds the elongation limit and causes cracking. Our company prevents cracking through three measures: first, selecting 6063-T5 with good elongation; second, precisely controlling bending speed to avoid local stress concentration caused by excessive speed; third, verifying by trial bending before batch processing to confirm no cracking before mass production.

Q5: How is inner wrinkling prevented during small-radius bending?

A: During small-radius bending, the inner side of the profile is under compressive stress; the smaller the radius, the greater the compressive strain, and the more likely wrinkling and creasing occur. Our company prevents wrinkling through two measures: first, adding inner-cavity supports in the mold to support the profile from the inside during bending; second, precisely controlling bending speed to avoid material buildup caused by excessive slowness.

Q6: How is small-radius bending charged?

A: Pricing is based on cross-section complexity, bending radius and wall thickness. Conventional cross-sections are priced per piece; special-shaped profiles and small radii require additional evaluation of mold and labor costs. Free sample-based evaluation and quotation are provided; please contact Manager Du at 13611846009.

Q7: What is the MOQ and lead time for small-radius bending?

A: The MOQ is 50kg, supporting small-batch sampling. The sample lead time is 7-10 days (requiring tuning of bending parameters and molds), and batch delivery is 10-20 days after sample confirmation. Because small-radius bending must ensure no cracking, no wrinkling and accuracy control, we recommend that the customer confirm the first-article effect before batch production.