Key Info of Stamping

Definition of Metal Stamping

Metal stamping is a process that uses a punch and a die to deform or break iron, aluminum, copper and other plates and special materials to achieve a certain shape and size.
Metal stamping is sometimes also called sheet forming, but there is a slight difference. The so-called sheet forming refers to the use of sheets, thin-walled tubes, thin profiles, etc. as raw materials. The forming method of plastic processing is collectively called sheet forming. At this time, the deformation in the direction of the thick plate is generally not considered.

Application of metal stamping

Springs, car parts, game hardware accessories, remote control 3D parts, metal stamping, various metal materials

Process classification of metal stamping

The stamping process can be roughly divided into two categories: separation process and forming process (which can be further divided into bending, drawing and forming). The separation process is to separate the stamping parts and the blanks along a certain contour line during the stamping process, and the quality of the separated section of the stamping parts must also meet certain requirements; the forming process is to make the stamping blanks undergo plastic deformation without damage and transform them into the required finished product shape, and at the same time, they should also meet the requirements of dimensional tolerance and other aspects.
According to the temperature during stamping, there are two methods: cold stamping and hot stamping. This depends on the strength, plasticity, thickness, degree of deformation and equipment capacity of the material, and the original heat treatment state and final use conditions of the material should be considered.

1. Cold stamping metal processing at room temperature is generally suitable for blanks with a thickness of less than 4mm. The advantages are no need for heating, no oxide scale, good surface quality, easy operation and low cost. The disadvantage is that there is a work hardening phenomenon, which makes the metal lose its ability to deform further in severe cases. Cold stamping requires the thickness of the blank to be uniform and the fluctuation range to be small, and the surface to be smooth, spot-free and scratch-free.
2. Hot stamping is a stamping method that heats metal to a certain temperature range. The advantages are that it can eliminate internal stress, avoid work hardening, increase the plasticity of the material, reduce deformation resistance, and reduce the power consumption of the equipment. (Source: China Machinery Network)
3. Die structure: The die is a tool that separates or deforms the sheet metal. A typical die consists of an upper die and a lower die. The die handle of the upper die is fixed on the slider of the punch press and moves up and down with the slider, while the lower die is fixed on the workbench of the punch press.
   The punch and the die are the working parts of the die that deform or separate the blank, and are fixed to the upper and lower templates with pressing plates. The upper and lower templates are respectively equipped with guide sleeves and guide columns to guide the alignment of the punch and the die. The guide plate and the positioning pin are used to control the feeding direction and feeding length of the blank respectively. The function of the stripper plate is to make the workpiece or blank come off the punch after stamping.
4. Classification of dies
   The die is an indispensable die in stamping production. Punching dies can be basically divided into three types: simple dies, continuous dies and compound dies.
   (1) Simple punching dies Simple punching dies are dies that only complete one process in one stroke of the punching machine. During operation, the strip material is fed between the two guide plates 9 on the die until it hits the positioning pin 10. When the punch presses downward, the punched part (or scrap) enters the die hole, while the strip material clamps the punch and moves upward with the punch. When the strip material hits the stripping plate 8 (fixed on the die), it is pushed down, so that the strip material continues to be fed between the guide plates. Repeat the above actions to punch out the second part.
   (2) Continuous punching dies A die that completes several punching processes at different parts of the die in one stroke of the punching machine is called a continuous die. During operation, the positioning pin 2 is aligned with the pre-punched positioning hole, the upper die moves downward, the punch 1 performs blanking, and the punch 4 performs punching. When the upper die returns, the stripping plate 6 pushes the scrap material off the punch. At this time, the blank 7 is fed forward to perform the second punching. This cycle is repeated, and the feeding distance each time is controlled by the stop pin.
   (3) Compound die A die that completes several stamping processes at the same part of the die in one stroke is called a compound die. The biggest feature of a compound die is that there is a punch and die 1 in the die. The outer circle of the punch and die is the punch cutting edge of the blanking die, and the inner hole becomes the drawing die. When the slider moves downward with the punch and die, the strip material is first blanked in the punch and die 1 and the blanking die 4. The blanked part is supported by the drawing punch 2 in the lower die. When the slider continues to move downward, the die moves downward to draw. The ejector 5 and the unloader 3 push the drawn part 9 out of the die during the return stroke of the slider. Compound dies are suitable for stamping parts with large output and high precision.
5. Basic stamping process The main basic processes of stamping are blanking, punching, bending and drawing.
   (1) Blanking and punching Blanking and punching are processes for separating blanks.
   The processes of blanking and punching are exactly the same, but they are used for different purposes. In blanking, the separated part is the finished product, and the remaining surrounding is waste; punching is to obtain a hole, the punched sheet is the finished product, and the separated part is waste. Blanking and punching are collectively called blanking. The punch and die of the blanking die have sharp edges, and there is a gap between the punch and the die equivalent to 5%-10% of the plate thickness to ensure that the cut is neat and has few burrs.
   (2) Bending Bending is to make the workpiece obtain various shapes of bends. The working part of the bending die that bends the workpiece should have an appropriate fillet radius r to avoid cracking when the workpiece is bent.
   (3) Drawing: Drawing is the process of making a flat blank into a cup or box-shaped part. The edges of the punch and die of the drawing die should be rounded to avoid cracking of the workpiece. There should be a gap slightly larger than the thickness of the sheet between the punch and the die (generally 1.1-1.2 times the thickness of the sheet) to reduce friction. In order to prevent wrinkles, the edge of the blank needs to be pressed with a pressing plate (binder ring). The actual drawing process of the product will produce cracking defects, please see
   Sheet metal stamping is a processing method that uses a die to separate or deform the sheet metal. Because the sheet metal does not need to be heated in most cases, it is also called cold stamping, also referred to as cold stamping or stamping.
   Commonly used plates are low-carbon steel, stainless steel, aluminum, copper and their alloys, which have high plasticity and low deformation resistance and are suitable for cold stamping.
   Sheet metal stamping is easy to mechanize and automate, with high production efficiency; the stamping parts are accurate in size and good in interchangeability; the surface is smooth and does not require mechanical processing; it is widely used in manufacturing industries such as automobiles, electrical appliances, instruments and aviation.
   3.2.1 Punch press structure and working principle
   There are many types of punch presses, and the most commonly used is the open punch press. The motor drives the large flywheel to rotate through the V-belt. When the pedal is pressed, the clutch connects the large flywheel to the crankshaft and rotates, and then the slider moves up and down along the guide rail through the connecting rod to perform stamping. When the pedal is released, the clutch is disengaged, and the brake immediately stops the crankshaft from rotating, causing the slider to stop at the highest position.Professional terminology for metal stamping

Professional terminology for metal stamping

Metal stamping parts are products after a series of processes, and they have different names in different processes, which are the professional terms we often say. Now let’s take a look at the common professional terms about metal stamping parts.
First, drawing: a stamping process that turns straight raw materials or process parts into hollow parts, or further changes the shape and size of hollow parts. During drawing, hollow parts are mainly formed by the material outside the bottom of the punch flowing into the die.
Second, trimming: a stamping process that uses metal stamping dies to trim the edges of the forming process so that it has a certain diameter, a certain height or a certain shape.
Third, punching: a stamping process that separates waste from materials or process parts along a closed contour to obtain the required holes on the material or workpiece.
Fourth, flanging: a stamping process that turns the material into a side-standing short edge around the outer curve.
Fifth, flanging: a stamping process that turns the material into a side-standing flange around the inner hole.
Sixth, blanking: a stamping process that separates the material along a closed contour, and the separated material becomes a workpiece or process part, most of which are planar.
Seventh, shaping: a stamping process that relies on material flow to slightly change the shape and size of the process parts to ensure the accuracy of the workpiece

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