AMADA have compiled some useful data which may assist engineers in the daily business of sheet metal design and production. Page

Transcription

1 Contents AMADA Section AMADA have compiled some useful data which may assist engineers in the daily business of sheet metal design and production. Page Punch Press Tonnage Calculation Minimum Hole Diameter Burring Hole Countersink Hole Correct Tool Heights Die Clearance Press Brake Bend Allowance - 90 : Mild Steel Bend Allowance - 90 : Stainless Steel Bend Allowance - 90 : Aluminium Hemming Tonnages The information and data contained within this reference section is for guidance purposes only. AMADA cannot accept any responsibility for typographical errors or mistakes contained herein. 127

2 Press Brake Bend Allowance - 90º Example 1 - Bending 1mm mild steel in a 6mm V die If (f) = Elongation factor If (d) = Blank development size d = ( ) - 2f d = 60 - (2 x 0.87) d = 58.26mm The following tables show the elongation factor (f) of mild steel, stainless steel and aluminium during a 90 bend. V = V - width (mm) t = material thickness (mm) f = bend allowances (mm) Mild Steel V t

3 Bend Allowance - 90º Press Brake V = V - width (mm) t = material thickness (mm) f = bend allowances (mm) Stainless Steel t V Aluminium t V

4 Press Brake Hemming Tonnages Hemming is a form of bending requiring higher amounts of tonnage than standard Air Bending. The tables below show the tonnage required for hemming and seaming operations. Mild Steel Bending Shape Sheet Thickness (mm) c 2t Required Tonnage C Required Tonnage 2t Note: Required tonnage is given per 1 metre length Stainless Steel Bending Shape Sheet Thickness (mm) c 2t Required Tonnage C Required Tonnage 2t Note: Required tonnage is given per 1 metre length 130

5 Tonnage Calculation Punch Press The punching tonnage is calculated by using the following formula: Length of the cut edge (mm) x Material Thickness (mm) x Tensile Strength (kg/mm 2 ) 1000 Example 1 Rectangle 50 x 10 in 2.0mm Stainless Steel Tonnage Required = ( ) x (2.0) x (60) 1000 Tonnage Required = 14.4 Tonnes Example 2 30mm Diameter in 1.5mm Mild Steel Tonnage Required = (3.142 x 30) x (1.5) x (40) 1000 Tonnage Required = 5.7 Tonnes Minimum Hole Diameter As a general guideline, the following table shows the minimum diameter (mm) of a punched hole with regards to material thickness. t = Material Thickness Material Type Minimum Hole Diameter Mild Steel 1.0 x t Aluminium 1.0 x t Stainless Steel 2.0 x t It is possible to punch smaller hits, please contact Tooling Hotline for assistance. 131

6 Punch Press Burring Hole The table below shows the pre-pierce (mm) and burred hole (mm) sizes for Mild Steel. Pre-Pierced Hole (øa) Nominal Material Thickness Burr 0.8mm 1.0mm 1.2mm 1.6mm 2.0mm 2.3mm Hole (øb) Tap Size M2.6 x M3 x M4 x M5 x M6 x ø A ø B t Countersink Hole The table below shows the nominal pre-pierce hole (mm) sizes required for a countersink operation for Mild Steel. Screw Size Material Thickness (mm) M2 x0.4 M2.5 x0.45 M2.6 x0.45 M3 x0.5 M4 x0.7 M5 x0.8 M6 x

7 Correct Tool Heights Punch Press The table below shows the correct tool height (mm) for Standard and NEX tooling Tool Style Setting Height Punch Body Only Die Only A Station Standard A Station NEX B Station Standard B Station NEX C Station D Station E Station Note: i) The Punch setting height is the measurement taken from the top of the Punch Assembly head to the bottom cutting edge of the punch body, not the bottom of the guide or stripper plate Die Clearance The table below shows the recommended die clearances for a range of materials and thicknesses. Material Thickness Mild Steel Stainless Steel Aluminium Copper Brass 0.8mm mm mm mm mm mm 1.0mm mm mm mm mm mm 1.5mm mm mm mm mm mm 2.0mm mm mm mm mm mm 2.5mm mm mm mm mm mm 3.0mm mm mm mm mm mm 3.2mm mm mm mm mm mm 3.5mm mm mm mm mm mm 4.0mm mm mm mm mm mm 4.5mm mm mm mm mm mm 5.0mm mm mm mm mm 5.5mm mm mm mm mm 6.0mm mm mm mm mm Notes: i) The figures in the above chart are given as a range, for example mm For mechanical machines choose the smaller die clearance of the range For hydraulic machines choose the larger die clearance of the range ii) For Galvatite and Zintec materials, use Mild Steel as a guide iii) The figures above are a guideline only. Please refer to your Machine Operators Manual for more specific details 133

8 General Further Information 134