MANUFACTURING – HEET METAL & FORMING CALCULATOR
Hem Flange Radius
A precise tool.
What is the Hem Flange Radius & How does it work?
A hem is a folded edge that adds stiffness and eliminates sharp edges on sheet‑metal parts, commonly used in enclosures, brackets, and ductwork.
The flat‑hem clearance (C) is the distance left between the original sheet surface and the inner face of the hem after bending; it controls the amount of material that must be stretched.
The resulting hem flange radius (R) can be estimated from the clearance and the sheet thickness (t) using the relationship
R = \frac{C^{2} + (t/2)^{2}}{2C}
R = hem flange radius (mm)
C = flat hem clearance (mm)
t = sheet thickness (mm)
C = flat hem clearance (mm)
t = sheet thickness (mm)
Parameters
Result
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Frequently Asked Questions
What is a hem flange radius in sheet metal?
The hem flange radius is the radius of the folded edge created when bending sheet metal to add stiffness and prevent sharp edges.
How do I calculate the flat-hem clearance (C)?
Flat-hem clearance (C) is the distance between the original sheet surface and the inner face of the hem after bending, controlling material stretch during the process.
What factors affect the hem flange radius?
The hem flange radius is influenced by the flat-hem clearance (C) and the sheet thickness (t).
Can you explain the formula for calculating the hem flange radius?
The formula R = (C^2 + (t/2)^2) / 2C is used to estimate the hem flange radius from the clearance and sheet thickness.
Why is it important to control the flat-hem clearance in sheet metal work?
Controlling the flat-hem clearance ensures proper material stretch, preventing defects and ensuring a smooth, uniform bend in sheet metal parts.
Results are for informational purposes only and do not constitute professional advice.