Air bending force chart

Mild steel

Die opening
V
4 6 7 8 10 12 14 16 18 20 25 32 40 50 63 80 100 125 160 200
Minimum flange length
bmin
2.8 4 5 5.5 7 8.5 10 11 13.5 14 17.5 22 28 35 45 55 71 89 113
Bending radius
ir
0.7 1.0 1.1 1.3 1.6 2.0 2.3 2.6 3.0 3.3 4.0 5.0 6.5 8.0 10 13 16 20 26
Thickness (t) →
0.5 mm 40 30
0.6 mm 60 40 40 40
0.8 mm 70 70 50 40
1.0 mm 110 100 80 70
1.2 mm 140 120 100 80 70 60
1.5 mm 170 150 130 110 90 80
2.0 mm 220 190 170 150 130 110
2.5 mm 280 250 220 180 140
3.0 mm 340 300 240 190 150
3.5 mm 330 260 200 160 130
4.0 mm 430 340 270 210 170
4.5 mm 440 340 270 210
5.0 mm 520 420 330 260 210
6.0 mm 750 600 480 380 300 240
7.0 mm 520 410 330 260
8.0 mm 850 680 530 430
9.0 mm 670 540 430
10 mm 850 670 530 420
12 mm 960 780 600 550
15 mm 950 750
Air bending force chart for mild steel (Rm≈450 N/mm2)

Stainless Steel

Die opening
V
4 6 7 8 10 12 14 16 18 20 25 32 40 50 63 80 100 125 160 200 250
Minimum flange length
b min
2.8 4 5 5.5 7 8.5 10 11 13.5 14 17.5 22 28 35 45 55 71 89 113 140 175
Bending radius
ir
0.7 1.0 1.1 1.3 1.6 2.0 2.3 2.6 3.0 3.3 4.0 5.0 6.5 8.0 10 13 16 20 26 33 41
Thickness (t) →
0.5 mm 60 50
0.6 mm 90 60 60 60
0.7 mm 120 80 80 60 60
0.8 mm 110 110 80 70
0.9 mm 130 120 100 80 70
1.0 mm 170 150 120 110 80
1.2 mm 210 180 150 120 110 90
1.5 mm 200 170 150 130 120
2.0 mm 330 290 260 230 200 170
2.5 mm 390 350 300 250 190
3.0 mm 510 450 360 290 230
4.0 mm 650 510 410 320 260
5.0 mm 780 630 500 390 320
6.0 mm 900 720 570 450 360
8.0 mm 1020 810 650 510
10 mm 1280 1010 800 630
12 mm 1440 1170 900 830
15 mm 1800 1410 1140
20 mm 2500 2080 1670
25 mm 3150 2550
30 mm 3600
Air bending force chart for stainless steel (Rm≈700 N/mm2)

Considering material thickness (t) and die opening (V) the table below shows the most important bending data:
  • Minimum bendable flange length bmin
  • Bending radius ir on the sheet metal
  • Press force F in KN / m