#### CALCULATING PUNCHING TONNAGE

To calculate punching tonnages use the following shear strength value chart with either the Inch or Metric formulas. To ensure safe operation,
it is recommended that any questionable tonnage conditions be reviewed thoroughly with your press manufacturer.

 MATERIAL TONS PER SQ INCH METRIC TONS PER SQ CM Aluminum 1100-0 3003-0, 6061-0 5.0 0.71 Aluminum 2024-0 3004-H36, 5052-H32 10.0 1.41 Brass & Aluminum 2025-T6, 6152-T6 17.5 2.46 Mild Steel & Bronze 27.5 3.87 Stainless Steel 55.0 7.74

Formula – Inches
Linear inches x Material thickness in inches x Tons per square inch = Job Tonnage Requirement
Formula – Metric
Linear centimeters x Material thickness in centimeters x Metric tons per square centimeters = Job Tonnage Requirement

EXAMPLE:  How many tons are required to punch (15) fifteen .375″ / 9.52 mm diameter holes in 16-gage (.06″ / 1.52 mm) mild steel?

Inch
Using the formula of Circumference = 3.1416 x Diameter, determine the linear inches of one .375″ diameter hole (.375 x 3.1416 = 1.178″). Multiply by 15 to calculate total linear inches (15 x 1.178 = 17.672″).  Select the proper Shear Strength value from the chart above.

17.672″ X 0.06″ X 27.5 = 29.2 Total Tons
29.2 X 1.1 = 32.1 Tons

Metric
Using the formula of Circumference = 3.1416 x Diameter, determine the linear centimeters of one 9.52 mm diameter hole (9.52 x 3.1416 = 29.91 mm, or 2.99 cm).  Multiply by 5 to calculate total linear centimeters (15 x 2.99 = 44.85 cm).  Select the proper Shear Strength value from the chart above.

44.85cm X .152 cm X 3.87 = 26.38 Metric Tons