onnage 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 b e it portions or the entire circumference of a circle, the s um 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 us e tensile strength of material. SHEAR STRENGTHS OF VARIOUS METALS MATERIAL
SHEAR (PSI)
MATERIAL
Aluminum
-
Steel
SHEAR(PSI)
Sheet
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
