Press Brake Tonnage Calculator

Instructions: Input data into the required fields for your material and punch & die configuration. This estimates the tonnage required to complete a 90° bend. (Yield and Tensile Material chart below)

Tensile Strength (PSI)
Material Thickness (inches) - T
Die Width (inches) - W
Punch Radius (inches)
K Factor
Die Ratio (W/T)
Bend Radius - Inside
Estimated Air Bend Radius

Bend Radius - Outside
Estimated Air Bend Radius

Minimum Between Bends
Minimum Leg Length for Die Width

Tonnage Required (per foot of Bend)
Total Tonnage for Bend
Overall Length
FT (required)
Constants (Press Brake Tonnage):
Bend Length (inches)
Friction Coefficient
Calculated Value of Force
Bend Angle (degrees)

DISCLAIMER: Actual bending force is affected by many factors such as friction between the material and the die, material thickness, material strength variations, rolling direction of the steel, work hardening and other parameters. This estimator calculates a force representative of the pressbrake requirement for air bending. Sizing of a machine or available die width should allow for up to 20% additional capacity. We make no guarantee of actual force required to make a bend in a specific part.


Other NumberGradeYield Str. Min. Tensile Max. Tensile Min. Rad. Recom.
Vee Die
 1015 290005000065000  
 1020 320005800073000  
 1025 340007000085000  
A36  3600058000800001.5T8T - 12T
A283  3000055000600001.5T8T - 10T
A570 303000049000640001T8T  
A572 424200060000750002T10T - 12T
  656500080000950004T14T - 16T
A588CORTENB5000070000850003T10T - 12T
A606  5000070000850002.5T8T - 12T
A607 454500060000750001.5T8T - 10T
  505000065000800002T10T - 12T
  606000075000900002.5T12T - 14T
A611 A250005200067000.5T 
A656 505000060000750001.5T8T - 10T
  60600007000085000 8T - 10T
  70700008000095000 8T - 10T
  8080000950001100001.5T8T - 10T
 A607606000070000850001.5T8T - 10T
  8080000900001050002T10T - 12T
A907 30300004900064000  
 AR360  177000192000  
 AR (235) 70000115000130000  
Other NumberGradeYield Str.Min. TensileMax. TensileMin. Rad.Recom. Vee Die
 S33228 270007300088000  
 S35315 3900094000109000  
A176S32803 7200087000102000  
 S42000420 100000115000  
A693 630160000185000200000  
Other Number GradeYield Str. Min. Tensile Max. Tensile Min. Rad. Recom. Vee Die
B2091100  1400024000  
 3003  1700030000  
 5005  1800030000  
 5052  3100044000  
 5083  4000059000  
 5086  4000054000  
 5454  3600047000  
 2024  3000063000  
 6061  2000042000  
B2216063  1300035000  
 7075  3300083000  

Bend Allowance Calculator

Bend Allowances

Bend allowance is the amount of metal to be added to the total layout. The most important considerations when bending metal is the min. bend radius. When bends are made smaller than the required min. radius, metal will crack at the outside heel of the bend. The min. radius of a bend is determined by the hardness and thickness of the metal. There are four methods for finding bend allowances. In the form below uses the empirical formula. It is the most accurate because it takes into account the shifting of the neutral line, slightly inward, when the metal is bent. The following form must be filled in with decimal equivalants.


Radius of Bend:  
Inches (decimel equivalent)
Thickness of Material:  
Inches (decimel equivalent)
Angle of Bend:  
Bend Allowance:  


Punching Tonnage Calculator

Tonnage for Round Punches

The following form will help you calculate how much tonnage is needed to punch round holes through a given thickness of metal. There are some limitations that you should be aware of. If you do not need a flat slug you can lower the tonnage required by adding a shear cut to the punch. Maxium amount of shear will cut tonnage in half as long as you have enough stroke movement on the punch. All input into the form below should be placed in decimal equivalants. Following are thickness tolerances on galvanized steel. Note: for holes 5/16" or less, the material thickness can not exceed the diameter of the hole being punch.


Diameter of Hole:   
Inches (decimel equivalent)

Material Thickness:  

Inches (decimel equivalent)
Tonnage Required: