Engineering Tools
Tonnage Calculation:
Use the guidlines below to calculate the needed tonnage for your stamping project.
General Formula for Press Tonnage Required:
Determine the approximate press tonnage needed to stamp a part based on linear inches of cut.
For Steel: Material Thickness X Inches of Cut X 25 = Press Tonnage
Example:
Need: 2" Square washer from .088 thick steel
Base Material: 2 ½" coil X 2 ½" progression
I
Calculation:
2 + 2 + 2 + 2 = 8
1" circle perimeter (P D) 3.14 X 1 " = 3.14
Total Inhes of Cut = 8 + 3.14 = 11.14
Tonnage Required:
.088 Thick X 11.14 X 25 (factor) = 24.5 tons
Blanking or Perforating Pressures:
Blanking or Perforating pressure (in tons) equals the total length of cut or cuts be it portions or the entire circumference of a circle, the sum of a square, rectangle or triangle or the entire total circumference of a number of holes multiplied by the material thickness, multiplied by the shearing strength of material. For answer in tons, the shearing strength must be converted from pounds/square inch (PSI) into tons/square inch by dividing by 2000.
Example:Mild steel (shearing strength) = 50,000 PSI/2000 = 25 tons/square inch
For drawing, use same method except use tensile strength of material.
| SHEAR STRENGTHS OF VARIOUS METALS | |||
MATERIAL |
SHEAR (PSI) |
MATERIAL |
SHEAR(PSI) |
| Aluminum Sheet | - |
Steel | |
| Soft | 15,000 |
.10 Carbon (Soft) | 45,000 |
| ½ Hard | 19,000 |
.25 Carbon (Mild) | 50,000 |
| Full Hard | 25,000 |
.50 Carbon | 70,000 |
| Brass Sheet | - |
.75 Carbon | 80,000 |
| Soft | 30,000 |
1.00 Carbon | 85,000 |
| ½ Hard | 35,000 |
1.2 Carbon | 94,000 |
| Full Hard | 40,000 |
1.20 Carbon (Tempered) | 190,000 |
| Copper | - |
Silicon | 65,000 |
| Rolled | 28,000 |
Stainless (18-8) | 70,000 |
| Monel Metal | - |
Nickel (3 ¼%) | 82,000 |
| Rolled | 65,000 |
Nickel (5%) | 85,000 |
