What is precision blanking?
First of all, we should know what is blanking? The stamping blanking process almost same with punching and trimming.
No matter what kind of stamping parts must have a blanking step to remove the material which you do not need. Sometimes blanking designed together with punching with one mold, we called it compound die stamping. The blanking process requires a blanking press, sheet metal stock, blanking punch, and blanking tool. Put the sheet metal on the blanking die, operate the blanking press, the blanking die will cut the sheet metal into required shape.
The blanking dies consists of two part: upper punch and bottom die. When they punch together, the fed sheet metal will be cut into customized shape. Upper punch and bottom die are made of tool steel or carbide steel. The carbide steel for tooling must be heat treated to get good strength and improve the surface abrasion performance. Between the punch and die, there have a small clearance, typically 10-20% of the material thickness. When the punch impacts the sheet, the metal in this clearance quickly bends and then fractured. The scraped material sheared off from the stock sheet metal. This is the whole process of blanking, and it mostly is the first step of manufacture for the stamping part. And it is also the simplest step compare with the whole process. Punching and trimming process is the same as blanking.
Typical blanking part with big burrs and rough edge, if the material thickness between 2.5mm to 4mm, there have 3 obvious zones on the cut-off surface, we call it rounded zone(rollover zone), fine zone(shear zone), torn zone(crack zone).
Blanking deformation process with stamping part
Chapter 1: What is Precision Metal Stamping?
Precision metal stamping is widely used in manufacturing processes because it is a fast and cost-efficient process of producing precision metal parts used in many industries.
Precision metal stamping China is the process of punching marks, 3D shapes, or any other type of design into flat material surfaces.
Metal stamping China also refers to the power of punching machinery and the use of moulds as metal plate forming tools to produce punching separation or plastic deformation effects in order to achieve the production technology of different parts, sizes, shapes, and performance requirements.
The metal press can perform a wide range of processes such as punching, tooling, notching, bending, embossing, flanging, coining, etc.
The precision die stamping machine works by exerting a high level of force to engrave dies and forms onto the surface material. Metals such as steel, copper, copper alloys, brass alloys, stainless steel, aluminium, etc are used in the metal stamping industry.
Precision die and stamping is widely used for the production of a wide range of products. The precision metal stamping in China can be executed as a single-stage operation, where each stroke of the metal press produces the desired shape on the sheet metal, or in a series of stages.
The growing demand for precision metal stamping parts in industries such as medical, automotive, aerospace, etc, has pushed the precision metal stamping industry to the forefront of manufacturing industries. Stamping technology is widely used in manufacturing engineering for 3D components, cutting, or other special requirements. Precision metal stamping in China offers a high level of design flexibility for defining and implementing the tiniest details with tight tolerances and unique configurations.
It is possible to create custom applications due to the adaptability of high precision stamping, with tools designed for the requirements of each application. This however makes precision die stamping an ideal solution for large scale productions of complex parts.
1.2. Equipment Used
Metal stamping China is a manufacturing technology that can make use of sheets or plates of different thickness into desired shapes by mechanical stamping and it does not change the thickness of the original material during the manufacturing process.
There are two main types of precision metal stamping China machines; mechanical presses and hydraulic presses. These two processes have unique features that are suitable for particular purposes. The characteristic of the two types of precision machines are:
Mechanical presses- The mechanical press uses a mechanical flywheel to transfer and store energy. The punches range between 5mm to 500mm, depending on the particular press. The processing speed also varies, usually falling between the range of 20 and 5000 strokes per minute. Mechanical presses come in different sizes, ranging from 20 to 6000 tons.
Hydraulic presses- In hydraulic press stamping, hydraulics is used to apply pressure to materials. Hydraulic pistons displace fluid with a force level proportional to the diameter of the piston head, which allows an advanced degree of control. The adjustable stroke and speed capabilities can deliver full power during any melting point in the stroke. Hydraulic presses usually vary in size from 20 to 10,000 tons and offer stroke sizes from about 10mm to 800mm.
1.3. Metal Stamping
The metal stamping China process requires knowledge of metals, their properties, and possible outcome after processing. All these and the design of the final product gives precision stamping product manufacturers the information needed to run a simulation before production can begin.
Simulations are required to predict information such as; material strength, design weakness and possible breaks or cracks after production. Once the simulation is completed, the completed computer model is transferred to the presses.
The presses used for precision metal stamping in China are capable of exerting forces between 10 and 50,000 tons. These forces can cut, stretch, and fed blank sheet metals into them. The precision die and stamping machines are highly automated, therefore, human errors are very low during production.
The type of material used in the precision metal stamping process is important to decide how much force is needed to cut and give it the desired shape.
Precious metals: Gold, silver and platinum may be expensive but there are some industries that use these metals for their production in the metal stamping industry.
Ferrous metals: These include iron-based alloys, such as stainless steel. Low cost and lower unit production prices make them the most commonly used in stamping operations.
Non-ferrous metals: Brass, bronze and zinc.
Speciality metals: Titanium and nickel. These types of metals are made for specific applications.
In the metal stamping China process, the blank sheet metal moves through a series of tools to shape and form the metal. In the precision die stamping machine, each die performs a unique and different task for each product. It is possible for cutting and shaping to occur during the production process. Both cutting and shaping require specialized dies.
Cutting- Die cutting involves creating specific shapes required to work a sheet metal towards its final form. During the metal cutting process, the metal will stretch and rebound, causing it to take the shape of the die. The following are the most common cutting processes:
- Trimming- Trimming is a finishing process that removes excess material from the metal piece. The excess material commonly referred to as addendum or offal can be recycled. Oftentimes, a smaller addendum can be used to produce smaller parts in another die.
- Piercing- Piercing is the opposite of blanking. Piercing often called perforating, is a metal cutting process that creates a round, square, or any other special shape within a sheet metal. The rest of the sheet metal is discarded while the shaped part moves to the next stage of production. The cutting punch that produces the hole is called the “pierce” or “perforating punch”, the hole in which it enters is called the “matrix”. Piercing is usually done on a smaller scale. The holes created through piercing can be used for fastening parts and making parts lighter. Examples include holes that hold special clips, clearance holes for wiring, etc.
- Blanking- Blanking creates the basic shape that will later be formed. That is, it is a method in which formed parts are cut free from sheet metal and pushed through the die. There are different types of blanks used in precision metal stamping in China: fully developed, partially developed, and underdeveloped.
A fully developed blank does not require additional trimming after it is formed. As a result of the differences in mechanical properties and thickness, inconsistencies in frictional values, fully developed blanks often exhibit minor inconsistencies in the parts edge dimension. If precision edge location is desired, secondary trimmings are often required.
A partially developed blank is shaped using just the required material so that excesses can be trimmed away later. This type of blank can be used when the trim tolerance is very small on the part. A partially developed blank requires more material to produce a part piece than a fully developed blank.
An underdeveloped blank starts as a basic shape, such as a square, rectangle, or any other shape that can be created using straight-line cuts. An underdeveloped blank does not require a special blanking die to cut out special shapes.