Metal Stamping

Sheet metal forming, or sheet metal fabrication, is the process of shaping and cutting metal sheets into specific components using various techniques. These techniques include bending, punching, shearing, and hydroforming, among others, to achieve the desired shapes and forms.

How Does Sheet Metal Fabrication Work?

Sheet metal fabrication makes use of a number of processes to transform a flat sheet of metal into metal parts that are durable and lightweight. Bending, shearing, punching, and hydroforming are all examples of processes that are used to form or cut metal sheets into the desired shape.

Sheet Metal Shearing

Cutting is similar to what the name suggests—shearing through a sheet of metal in a straight line or curve. It is a manufacturing process used to cut off a plate needed for a particular application, usually done with a shearing machine.

Sheet metal Cutting is defined as separating material into two parts. It utilizes shearing force to cut sheet metal and usually used for preliminary machining, cutting sheet metal to obtain the maximum outline size of the workpiece. The press can then further process these pieces to form the specific shape desired.

Shearing is a type of cutting, but it is limited to straight-line cutting of thin sheets.Cutting is a broader concept that includes shearing, laser cutting, plasma cutting, waterjet cutting, and punching, making it suitable for a wider range of applications.

Another common way to cut sheet metal——Laser Cutting

A laser cutter is a machine that uses a high-energy focused laser beam to cut into various plate or sheet materials.

Compared to stamping, laser cutting offers higher precision and flexibility, imposes less mechanical stress on the workpiece, has higher operating costs, and is slower, but stamping incurs mold costs.

Selection of gases for laser cutting:

Comparison of different gas cutting products

Our Laser Cutting Machine

Laser Power: 3500W

Cutting Range: 3070×1550×100 mm
Cutting Materials and Thickness: SS 20mm；SUS 10mm ;Aluminum 8mm

Positioning Accuracy: Usually within ±0.1 mm, ensuring precise cutting.
Rapid feed rate:  170 m/min for X and Y axes

Sheet Metal Punch

Sheet Metal Punching is a process where manufacturers cut holes in the metal. Most often, punches cut the holes shaped like circles or squares. It’s also an excellent way to apply an edge or border to the sheet.

Our NCT（Numerical Control Turret Punch Press） Machine

Nominal Force: 200 kN
Maximum Processing Dimensions: 4’ X 8’ sheets
Maximum Processing Plate Thickness: 6.4mm
Punching Accuracy: ±0.1mm and ±0.07mm (FA mode)
Max Feed Rate: X : 80 Y : 60  m/min

Our Hydraulic Punch Press Machine
Nominal Force:600kN,800kN,1100kN,1500kN,2000kN

Key Stamping Methods: Progressive, Transfer, Four-Slide, Deep Drawing, and Fine Blankin

Progressive Stamping

 A simultaneous completion of multiple punching processes (e.g. punching, dropping, trimming) in different positions in a single stroke.

And progressive Stamping is a high-efficiency production method using a sequence of dies in a progressive arrangement. Metal sheets or coils are fed continuously through each die station, where specific tasks like cutting, bending, or forming are performed. This process enables the production of complex parts with multiple features in a single operation, making it ideal for high-volume manufacturing.

Benefits:

1. High Volume Production: Progressive die stamping is incredibly fast, capable of producing large quantities of parts at a rate of 7 to 8 parts per minute, reaching up to 1,500 parts per hour.
2. Labor Efficiency: The process can operate automatically without constant supervision, reducing the need for manual labor and lowering overall costs.
3. Single Machine Operation: All stamping operations can be performed on one machine, minimizing the need for multiple setups.
4. Tooling Configuration: All die stations are integrated into a single die, producing parts in one continuous pressing operation.
5. Speed: Progressive die stamping is faster than other methods like transfer stamping, and can be run on less expensive equipment.

Challenges:

1. Technical Complexity: Setting up a progressive die system requires careful planning and precise calculations to ensure that the metal feeds at a consistent rate, protecting the dies from damage.
2. Cost: While efficient, the initial setup and equipment costs for progressive die stamping are higher than those for line or transfer stamping. The process demands advanced machinery and experienced operators.
3. Heavy Equipment: The machinery used for progressive die stamping is often bulky, which can increase space and logistical requirements.
4. Maintenance: If a single die station becomes damaged, the entire system must be halted for repairs or replacement, potentially causing significant downtime.

Transfer Stamping

Similar to progressive stamping. Instead of progressive stamping allowing the metal sheet to move continuously through the dies, transfer stamping utilizes mechanical systems to transfer the sheet from one station to another，with each die spaced evenly. It is particularly suited for larger and more complex parts that require additional operations or precise positioning.

Benefits:

1. Multiple Movements: Transfer stamping can perform two-axis and three-axis movements within a single cycle, enhancing flexibility. Each axis is represented by different colors in diagrams, showcasing the process’s complexity.
2. Automated Part Placement: Parts are automatically positioned using gauges or locators, ensuring precise placement for each operation.
3. Faster Production: Large parts can be quickly rotated, shifted, and positioned, allowing for rapid movement between stations.
4. Computerization: Servo-driven transfers can be programmed to adjust for part types, press speed, and stroke length, optimizing the process.
5. Reduced Turnaround Time: High volumes of parts are completed with less handling, waste, and labor costs, increasing overall efficiency.

Challenges:

1. Technical Planning: Transfer die stamping requires sophisticated technical monitoring and equipment. The process must be meticulously planned, tested, and adjusted to maintain quality standards.
2. Cost Considerations: The expertise needed for planning and design is both costly and time-consuming, making the overall process generally more expensive than progressive stamping.
3. Specialized Equipment: Dedicated equipment is necessary for controlling the flow of scrap and timing of insertions.
4. Process Oversight: Due to the high speed of production, it can be difficult to monitor the condition of the dies. Chips and protective sensors are essential to ensure operational safety.
5. Process Limitations: In two-axis operations, the sliding of parts from one die to another may slow down production rates, necessitating careful consideration of design and execution.

Deep Drawing Stamping

Deep Drawing Stamping is a metal forming process used to produce deep, hollow parts such as cylinders, boxes, or other complex shapes. In this method, a flat metal blank is placed over a die and pushed into the die cavity using a punch. As the metal undergoes plastic deformation, it conforms to the die’s shape, creating thin-walled parts with significant depth.Deep drawing is essential for producing round, rectangular, and even complex, irregular shapes, offering high precision and efficiency in mass production.

Four-Slide Stamping 

Four-Slide Stamping, or multi-slide stamping, is a metal forming process that uses four horizontal slides, controlled by cams, to perform multiple bends and shapes in one operation. It is ideal for creating small, complex parts with intricate designs and is widely used in industries like automotive and electronics. This method offers high precision, efficiency, and cost-effectiveness, making it suitable for high-volume production of detailed components.

Fine Blanking 

Fine blanking is an advanced precision cutting method developed from traditional stamping technology, primarily used to produce high-quality, burr-free parts. Unlike conventional blanking, fine blanking employs a specialized die design and processing technique to achieve smooth, crack-free cut surfaces across the entire material thickness. The process uses triple-action pressure, minimal die clearance, and rounded cutting edges to effectively suppress material tearing and lateral flow during shearing, resulting in high-precision, flat components. Fine blanking is commonly used in industries like automotive for parts such as gears and other components that demand exceptional edge quality and dimensional accuracy.

Key Characteristics of Fine Blanking

1. Minimal Burrs and Edge Deformation: Fine blanking results in minimal edge deformation, ensuring smooth and precise edges.
2. Large Bright Band Proportion: The bright band on the cutting surface typically covers around 90% of the material’s thickness, delivering a clean, polished finish.
3. High Cutting Surface Precision: Fine blanking creates a minimal fracture zone, offering significantly better cutting precision compared to conventional stamping, which facilitates better assembly performance.
4. Tear-Free Cutting via Triaxial Compressive Stress: Fine blanking employs a small die clearance and triaxial compressive stress to prevent tearing during cutting. This ensures the material undergoes plastic deformation throughout the process, leading to superior product quality.

Differences Between Fine Blanking and Conventional Stamping

1. Die Structure: Fine blanking uses a more complex die setup, including V-shaped edge rings and ejectors, which secure the material tightly before cutting. This reduces the likelihood of cracks and tearing, unlike conventional stamping, which lacks this level of material control.
2. Process Principles: Conventional stamping can cause tearing during the cutting process, whereas fine blanking prevents this by maintaining triaxial stress and applying uniform pressure across the material.
3. Application Scope: Fine blanking is particularly suited for parts requiring high flatness and edge quality. Its ability to tightly control the material during cutting results in parts with excellent surface precision, making it ideal for industries such as automotive and appliance manufacturing.

Fine Blanking Tooling Requirements

1. Precision Die Clearance: Fine blanking requires a minimal clearance between the punch and die (0.002–0.005mm) to ensure even pressure distribution and reduce the risk of material tearing.
2. Tool Strength and Wear Resistance: The tooling components must have high strength and stiffness to avoid elastic deformation during operation. Fine blanking punches and dies need to be highly wear-resistant to extend tool life.
3. High Guiding Accuracy: The fine blanking process demands precise tool alignment and guidance to ensure accurate cutting and maintain the die clearance.
4. Controlled Punch Depth: It is crucial to control the depth of punch penetration into the die, typically between 0.025mm to 0.05mm, to prevent damage to the cutting edges.
5. Exhaust and Wear Management: Proper exhaust design is essential for tool longevity, and wear and fatigue must be carefully monitored to maintain process efficiency.

These are the primary types of stamping processes.These techniques optimize efficiency and quality across industries like automotive and electronics. Understanding these methods enables manufacturers to meet specific requirements with greater accuracy and performance.