SHEET METAL PRESS BRAKE & FLANGING CAM

Sheet Metal Hemming, Flanging & Seam Flattening Calculator

Compute pre-bend acute angles (28°–35°), minimum return flange lengths, flat blank stretch deduction, and required press brake flattening tonnage for flat, open, and teardrop hems.

1. Material & Thickness

Material Alloy & Tensile Strength

Sheet Metal Thickness (T) [mm]

Nominal sheet gauge. Standard hemming is practical between 0.5 mm and 3.0 mm.

Seam Bend Length (L) [mm]

Total length of the hemmed edge along the press brake bed.

2. Hemming Geometry & Tooling

Hem Style & Configuration

Return Flange Length (Lf) [mm]

Dimension of the folded-back hem lip from the outside crease.

Stage 1 Acute Pre-Bend Angle [°]

Hemming CAM & Tonnage Results

Min Flange Return (Lmin)

6.00 mm

Minimum lip to seat into acute die

Stage 2 Flattening Force

24.5 Tons

Required press brake capacity

Blank Hem Allowance (ΔL)

7.80 mm

Added to flat DXF perimeter

Stage 1 Pre-Bend Force

6.2 Tons

30° V-die air bending load

Flat DXF Unfolding Formula:

                            Flat_Blank = Part_Base + L_flange - (0.43 * Thickness)
                        

Need Precision Flat DXFs for Press Brakes?

SpotItLive converts technical sketches, raster CAD prints, and logo profiles into unfolded, machine-ready DXF and SVG files with calibrated bend deductions.

Get Machine Vector Bundle (29 DKK)