Air Bending Tonnage Charts

diagram

Material Thickness and V Width

The distance across the die opening is known as the V-width. The appropriate V-width should be selected in accordance with the thickness of material being bent. The table below shows the optimum relationship between the material thickness and V-width, although in practise this relationship is often determined by specific requirements, including flange lengths (b), the components inner bend redius (ir) and the tonnage capacity of the machine and tooling.

Relationship of Material Thickness (t) and V Width

Material Thickness (t) mm	0.5 - 2.5	3.0 - 8.0	9.0 - 10.0	12.0 or more
V-Width	6 x t	8 x t	10 x t	12 x t

How to Read the Pressure Chart

If the material thickness and inner radius are known, the following information can be obtained from the chart below:

1. Tonnage required to bend material of 1 metre length

2. V-width to be used

3. Minimum bend flange length

Air Bending Tonnage Chart: Mild Steel

t mm	8	12	16	20	25	32	40	50	63	80	100	V
	5.5	8.5	11	14	17.5	22	28	35	45	55	71	b
	1.3	2	2.6	3.3	4	5	6.5	8	10	13	16	ir
0.5												F
0.6	4
0.8	5
1	8	6
1.2	12	8	6
1.4	15	11	9
1.6		15	11	9
2		22	17	13	11
2.3			23	17	15	12
2.6			28	22	18	14
3				30	24	19	15
3.2				34	27	22	17	14
3.5					33	26	20	16	13
4					43	34	27	21	17
4.5						44	34	27	21
5						52	42	33	26	21
6							60	48	38	30	24
7									52	41	33
9										67	54
10										85	67
12											96