Forming Chart

Tonnage Guidelines – Click here for a handy pdf!

Approximate pressure in tons per linear foot required to make 90 degree air bend in mild steel

Thickness Width of Female Die Opening
Guage Dec. 1/4 5/16 3/8 1/2 5/8 3/4 7/8 1 1 1/8 1 1/4 1 1/2 2 2 1/2 3 3 1/2 4 5 6 7 8 10 12
20 .036 2.6 2.2 1.6 1.2 1.0
18 .048 3.5 2.8 2.1 1.7 1.3
16 .060 5.3 3.7 2.8 2.2 1.7
14 .075 5.5 4.6 3.5 3.0 2.5 2.1
13 .090 6.4 5.5 4.3 3.6 3.2 2.8
12 .105 9.2 6.9 6.2 5.0 4.3 3.9 3.1
11 .120 10.1 8.0 7.0 6.1 5.3 4.3 2.9
10 .135 10.3 8.7 7.6 6.9 5.7 3.9
9 .150 11.9 9.8 8.8 7.0 5.0 3.7
7 .188 16.9 13.9 11.2 8.3 6.7 4.9
1/4 .250 27.5 22.1 15.0 11.6 9.6 7.9 6.7
5/16 .312 39.2 26.5 19.3 15.0 12.5 10.4 7.7
3/8 .375 42.7 31.2 23.8 19.5 16.3 12.4 9.6
7/16 .437 45.5 35.2 26.5 24.4 17.4 15.0 11.5
1/2 .500 48.5 39.5 33.2 24.6 19.5 16.1 13.4
5/8 .625 65.5 57.9 42.8 33.1 27.3 23.3 17.0
3/4 .750 92.3 68.1 53.0 43.2 36.2 26.9 21.0
7/8 .875 103.1 79.9 63.9 52.3 39.2 31.2
1 1.0 112.1 90.4 75.5 55.7 43.7

 

Shaded figures represent ideal conditions for light angle bending; punch with radius equal to metal thickness and die opening approximately 8 times the metal thickness. Resulting bend has inside radius approximately equal to metal thickness. If stock exceeds 1/2 inch in thickness, it is good practice to increase die’s opening to at least 10 times the metal thickness. Bending pressures required for other metals as compared to 60,000 P.S.I. tensile mild steel on chart.

Soft Brass
50% of pressure listed
Soft Aluminum
50% of pressure listed
Aluminum Alloy (heat treated)
Same as steel
Stainless Steel
50% more than steel
Chrome Molybdenum
100% more than steel

Press Brake Dies and Tooling