What is the definition of "double breakage"?
The condition of two separate deformation stages caused by insufficient clearance. Double breakage causes two burnished rings on the blank edge.

## Stamping Training

Class Information
 Tooling U-SME classes are offered at the beginner, intermediate, and advanced levels. The typical class consists of 12 to 25 lessons and will take approximately one hour to complete.
 Class Name: Die Cutting Variables 200 Description: This class describes the steps that take place during a cutting operation and shows how clearance impacts the cutting process. Includes an Interactive Lab. Difficulty: Intermediate Number of Lessons: 14 Language: English, Spanish

Class Outline
• Objectives
• What Is Die Cutting?
• Shearing Forces
• The Steps of Die Cutting
• Deformation
• Fracture
• Snap-Through
• Stripping
• Clearance
• Determining Clearance
• Insufficient Clearance
• Excessive Clearance
• Calculating Cutting Forces
• Summary

Class Objectives
• Describe the general force applied during die cutting.
• Describe specific forces that occur during die cutting.
• Identify the steps that take place during die cutting.
• Explain the deformation process.
• Explain the fracture process.
• Explain the snap-through process.
• Explain the stripping process.
• Define clearance.
• Define angular clearance.
• Describe the factors that determine proper clearance.
• Explain the result of insufficient clearance.
• Explain the result of excessive clearance.
• Describe the factors that determine cutting forces.

Class Vocabulary

Vocabulary TermDefinition
The enlarged section below the die opening that allows the blank to fall from the die.
A shearing operation that creates a hole in sheet metal by separating an interior section. The removed piece of metal is the desired part.
A practical term for the rough, fractured ring surrounding the edge of a blank.
The creation of a shiny, polished surface on metal due to a shearing action.
The space between the punch and the die that allows metal to be cut.
A force or pressure that attempts to flatten or squeeze a material.
A practical term for the burnished ring surrounding the edge of a blank.
The misalignment of components due to various stresses.
The moment during which the punch penetrates the sheet and metal flows into the die opening. Deformation and penetration cause the edge radius and burnished ring.
The condition of two separate deformation stages caused by insufficient clearance. Double breakage causes two burnished rings on the blank edge.
A rounded edge on a blank caused by the initial deformation as the punch begins to enter the die.
The moment during which cracks form and the blank separates with a tearing action. Fracture causes the roughened break off section on the edge.
A fluid designed to reduce friction and cutting forces during a stamping operation.
A shearing operation that creates an open hole in sheet metal by separating an interior section. The removed metal section is discarded scrap.
The ability of a material to resist forces that attempt to cause the internal structure of the material to slide against itself.
The cutting and separating of material without the formation of chips.
The moment during which the blank separates from the sheet and compressive forces are released from the die components.
A plate designed to remove sheet metal stock from the punch as it pulls away from the die during the operation.
The moment during which the punch retracts from the die and is removed from the sheet.
An angled surface that appears on the edge of a blank. Taper is the result of clearance between the punch and die.
The ability of a material to resist forces that attempt to pull it apart or stretch it.