How to Calculate Tonnage [Free Formula]

The Tonnage Formula is the pressure required in tons to cut a blank or contour using a flat faced punch with no shear. Tonnages can be calculated for forming, bending, cutting, drawing, and blanking operations. Having the ability to calculate the tonnages for a sheet metal project is vital for the completion and success of your project.

Formula

T = P x Th x C

T = Pressure required in tons

P = Perimeter of blank in inches

Th = Thickness of material

C = Constant (see common ones below)

Constant = The material shear strength/2000 pounds

Example

.050 CR Steel, 1/2 Hd; Cutting edge of 12 linear inches T

= 12 x .050 x 32

T = 20 tons required

Constants

Aluminum- Soft-11

T4/T6-15  

Steel- HR/Cold Rolled-27

1/2 Hard-32

Stainless Steel- Annealed-37

1/2 Hard-50

4130 AQ - 40

Brass- 1/2 Hard-22

Hard-25

Want more metalforming and metal fabrication tips?  Get your FREE copy of the original Dayton Rogers Red Book. This powerful book is your resource for all things metalforming and stamping.


 

Dayton Rogers is your trusted resource for sheet metal fabrication, metal stamps, metalforming and all your manufacturing company needs. Get a free quote today on your custom metal fabrication project.

LOCATIONS

  • MINNEAPOLIS 8401 West 35W Service Drive Minneapolis, MN 55449
  • TEXAS 1107 Commercial Blvd N Arlington, TX 76001
  • OHIO 2309 McGaw Road West Columbus, OH 43207
  • SOUTH CAROLINA 1020 Second Avenue Columbia, SC 29209