Die Set Types, Functions, and Stripper Systems
Die Set Types and Styles
There are various types of die sets, each designed for specific applications, material types, and production requirements.
Standard Die Set
A standard die set consists of the upper and lower die blocks and punch holders. It is used for general-purpose stamping operations.
It is commonly employed in blanking, piercing, and forming processes for producing parts from sheet metal.
Progressive Die Set
A progressive die set has multiple stages, with each stage performing a different operation on the material as it moves through the die.
This die set is used for high-volume production of complex parts.
Compound Die Set
A compound die set combines multiple operations (such as blanking and piercing) in a single press stroke. It is useful for simpler, high-volume applications.
Transfer Die Set
A transfer die set is designed for moving the workpiece from one station to another as part of a progressive or compound die set. This allows for more complex part formations.’
Function of Parts of a Die Set
A die set typically contains several parts that perform specific functions:
- Die Block: Holds the cutting or forming die and provides the base for all other components.
- Punch Block: Holds the punch and ensures it is aligned with the die.
- Punches: The tools used to cut or form the material in the die set. Punches press into the material to shape it or create holes.
- Die (Cavity): The component that shapes or cuts the material. The die contains the shape into which the punch is pressed.
- Stripper Plate: Used to strip the part away from the punch after it is formed. It ensures that the part is removed cleanly and does not remain stuck to the punch.
- Ejector: The ejector system helps push the finished part out of the die after it is formed, preventing it from sticking to the die or punch.
- Guide Pins and Bushings: These ensure proper alignment between the die and punch blocks during the operation.
- Bolts and Screws: These are used to hold the die set components together securely.
Stripper Categories and Types
Strippers can be broadly categorized into fixed and moving types, with variations designed for different needs in terms of the workpiece and tooling design.
Fixed Stripper
A fixed stripper is stationary and does not move during the punching operation. It typically holds the workpiece in place, pushing it away from the punch after the stamping or piercing operation.
Types of Fixed Strippers
Hook Pin Stripper
This type of stripper uses hook-shaped pins that engage with the workpiece to hold it in place during the operation. These pins prevent the part from being displaced or moved until the punch completes its cycle and the stripper removes it.
Box Strippers
A box stripper is a type of fixed stripper that surrounds the workpiece on all sides, providing more stability and ensuring accurate alignment during the punching operation. This type of stripper is generally used for more complex stamping operations where additional support is needed for the part.
Moving Stripper
A moving stripper operates in conjunction with the punch or die to push the part away from the punch during or after the operation. The movement of the stripper allows for more efficient and smoother separation of the part from the punch.
Types of Moving Strippers
Pressure Pad Type Strippers
The pressure pad stripper uses a pad that is spring-loaded or pneumatically activated to push the part off the punch. This type is commonly used in situations where the part is tightly attached to the punch and requires additional force to strip.
Guided Strippers
Guided strippers have a system of guides (such as pins or slots) that ensure the stripper moves along a fixed path to apply even pressure across the part. This design is used when precision and consistency are important in the stripping operation, especially when parts are prone to misalignment.