Notching is a sheet metal cutting operation in which material is removed from the edge or corner of a sheet.
The removed portion is scrap, and the remaining sheet is the product.
It is commonly used to prepare sheets for bending or forming operations.
In this article:
Notching in Sheet Metal
What is Notching?
Notching is a sheet metal cutting operation in which a portion of metal is removed from the edge or corner of a sheet.
👉 Cutting is done from the outer edge
👉 The removed piece is scrap
👉 It is a type of shearing operation
Working Principle
- The sheet is positioned in the die.
- A punch moves downward.
- Shear stress develops along the cutting edges.
- The unwanted edge portion is removed.
- The sheet remains with a notch.
Main Components
1️⃣ Punch
- Moving tool
- Shape equals required notch
2️⃣ Die
- Fixed tool
- Slightly larger opening (clearance provided)
3️⃣ Press Machine
- Mechanical or hydraulic
Clearance in Notching
Clearance = Gap between punch and die
Usually:
5–10% of sheet thickness
Proper clearance:
✔ Smooth cut
✔ Reduced burr
✔ Less tool wear
Notching Force Formula
Example
Given:
- Notch length = 60 mm
- Thickness = 2 mm
- Shear strength = 300 MPa
Required force = 36 kN
Types of Notching
1. Corner Notching
Removing metal from corners.
2. Side Notching
Cutting from side edge.
3. V-Notching
V-shaped notch for bending preparation.
4. Circular Notching
Semi-circular cut at edge.
Applications
- Preparing sheet for bending
- Box and enclosure manufacturing
- Structural sheet components
- Fabrication industries
- Automotive panels
Advantages
✔ Simple operation
✔ Fast production
✔ Useful for edge shaping
✔ Accurate notch shape
Disadvantages
✖ Burr formation
✖ Tool wear
✖ Limited to edge cutting
Difference Between Notching and Punching
| Feature | Notching | Punching |
|---|---|---|
| Cutting Location | Edge of sheet | Inside sheet |
| Product | Sheet with edge removed | Sheet with hole |
| Scrap | Removed edge portion | Slug |
Summary:
- Notching is an edge cutting operation.
- It is a type of shearing process.
- Clearance is necessary.
- Used mainly before bending operations.
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