Press Tool Calculation 2y20u

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 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 MATERIAL SHEAR(PSI) (PSI) Aluminum

-

Steel

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

190,000

Copper

-

1.20 Carbon (Tempered) Silicon

Rolled

28,000

Stainless (18-8)

70,000

Monel Metal

-

Nickel (3 ¼%)

82,000

Rolled

65,000

Nickel (5%)

85,000

65,000