TONNAGE CHARTS

PRESSURE IN TONS PER LINEAR FOOT REQUIRED TO MAKE 90 DEGREE AIR BEND IN MILD STEEL
THICKNESS
OF METAL
WIDTH OF FEMALE DIE OPENING
GAUGE INCHES 1/4" 5/16" 3/8" 1/2" 5/8" 3/4" 7/8" 1" 1.125" 1.25" 1.5" 2" 2.5" 3" 3.5" 4" 5" 6" 7" 8" 10" 12"
20
18
16
.036
.048
.060
2.9


2.2
4.0

1.7
2.9
5.6
1.2
2.2
3.6
1.0
1.6
2.7

1.3
2.2


1.7















14
13
12
.075
.090
.105





6.0


4.5
6.8
10.1
3.4
5.4
7.4
3.0
4.3
6.3
2.5
3.7
5.4
2.1
3.3
4.4

2.9
4.0


3.2











11
10
9
.120
.135
.150









10.5


8.8
11.3

7.2
9.6
13.1
6.2
8.4
11.9
5.4
7.0
9.0
4.3
5.6
6.7
3.2
4.1
5.2


3.5









7
1/4
5/16
.188
.250
.312















16.4


14.0
28.8

11.2
22.0
38.0
7.6
15.3
26.0
5.8
11.5
19.2
4.5
9.1
16.0

7.5
12.5

6.2
10.6


7.6





3/8
7/16
1/2
.375
.437
.500




















41.0


29.9
45.2

24.0
35.0
47.9
19.4
28.0
39.0
16.0
24.0
33.1
12.3
17.0
24.0

14.6
19.0

11.1
15.6


12.7


5/8
3/4
7/8
1"
.625
.750
.875
1.00






WITH THESE THICKNESS
IT IS USUAL PRACTICE TO
HAVE DIE OPENING AT LEAST
10 x METAL THICKNESS



69.5



58.0
92.0


42.2
69.0
104.0

32.4
52.2
80.0
112.2
26.0
42.2
63.0
90.0
23.0
36.0
52.5
76.0
16.5
27.0
39.4
56.2

21.0
31.2
44.0
AIR FORM
RADIUS
1/32 3/64 1/16 5/64 3/32 1/8 9/64 5/32 11/64 3/16 15/64 5/16 25/64 15/32 35/64 5/8 25/32 15/16 1.09" 1.25" 1.56" 1.87"
MIN. FLANGE
INS. DIM.
3/16 7/32 1/4 5/16 7/16 1/2 9/16 5/8 11/16 3/4 15/16 1.188" 1.438" 1.75" 2" 2.25" 2.75" 3.38" 4" 4.5" 5.5" 6.5"
PRESSURES IN RED ARE FOR DIES WITH FEMALE OPENINGS APPROX. 8 x METAL THICKNESS, WITH RADIUS
ON MALE DIE EQUAL TO METAL THICKNESS, AND ARE CONSIDERED IDEAL FOR RIGHT ANGLE BENDING.
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 ALLOYS (Heat Treated)...SAME AS STEEL
STAINLESS STEEL ...........50% MORE THAN STEEL
CHROME MOLYBDENUM ....100% MORE THAN STEEL
A36 STEEL ............30% MORE THAN STEEL

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