1. What is Tube Bend Allowance?

The Tube Bend Allowance (BA) is the length of the neutral axis between the tangent points of a bend in tube or pipe fabrication. It's crucial for determining the total length of material needed for a bent tube.

2. How Does the Calculator Work?

The calculator uses the fundamental bend allowance formula:

Where:

• \( BA \) — Bend allowance (meters)
• \( \theta \) — Bend angle (radians)
• \( CLR \) — Center line radius (meters)

Explanation: The formula calculates the arc length of the neutral axis through the bend, which remains unchanged during bending.

3. Importance of Bend Allowance Calculation

Details: Accurate bend allowance calculation is essential for proper tube fabrication, ensuring correct part dimensions and minimizing material waste in piping systems, handrails, and structural applications.

4. Using the Calculator

Tips: Enter bend angle in radians and center line radius in meters. Both values must be positive numbers. For degree to radian conversion, remember π radians = 180°.

5. Frequently Asked Questions (FAQ)

Q1: How do I convert degrees to radians?
A: Multiply degrees by π/180. For example, 90° = 90 × (π/180) = π/2 ≈ 1.5708 radians.

Q2: What is the neutral axis in tube bending?
A: It's the imaginary line in the tube's cross-section that neither stretches nor compresses during bending.

Q3: Does material thickness affect bend allowance?
A: This simple formula assumes thin-walled tubes. For thick-walled tubes, more complex formulas accounting for material properties may be needed.

Q4: What's the difference between CLR and inside radius?
A: CLR is measured to the centerline of the tube, while inside radius is measured to the inner surface. CLR = inside radius + (tube OD)/2.

Q5: Can this be used for sheet metal bending?
A: The principle is similar, but sheet metal bending typically uses different formulas accounting for material thickness and bend deduction.