A Special Expanding Collet Chuck is a custom-designed internal clamping (ID clamping) workholding device used to hold hollow, thin-wall, or delicate components from the inside diameter.
Unlike standard expanding chucks, special expanding collet chucks are engineered specifically for the component, ensuring uniform expansion, distortion-free clamping, and high concentricity.
They are ideal for applications where external clamping is not possible or may deform the part.
Applications
Special Expanding Collet Chucks are widely used in:
- CNC Turning of bushes, sleeves & pipes
- Thin-wall & precision hollow components
- Automotive & engineering parts
- Hydraulic & pneumatic components
- Bearing housings & cylindrical shells
- Facing, OD turning, boring & grinding operations
- Mass production & automated CNC lines
Key Features
- ✔ Uniform 360° internal expansion
- ✔ Distortion-free clamping for thin-wall parts
- ✔ High concentricity & repeatability
- ✔ Designed as per component drawing or sample
- ✔ Suitable for manual, pneumatic & hydraulic actuation
- ✔ Hardened & precision-ground expanding segments
- ✔ Fast loading/unloading, reduced cycle time
- ✔ Long service life with stable clamping force
Working Principle
The expanding collet chuck operates by axial movement of a draw bar or hydraulic piston, which forces the expanding segments outward.
This creates even radial pressure inside the bore, securely holding the component without ovality or surface damage.
Types of Special Expanding Collet Chucks
- Manual Expanding Collet Chuck
- Hydraulic Expanding Collet Chuck
- Pneumatic Expanding Collet Chuck
- Step Expanding Collet Chuck
- Long-Length Expanding Collet Chuck
- Thin-Wall Component Expanding Chuck
- Multi-diameter / Custom Expanding Chuck
Technical Specifications
- Clamping Type: Internal (ID expanding)
- Material: EN31 / EN24 / spring steel
- Hardness: 58–62 HRC
- Accuracy: ≤ 0.01 mm TIR
- Expansion Range: Custom as per bore size
- Mounting: Spindle nose / back plate / flange
- Customization: 100% application-specific
Advantages
- Prevents deformation of delicate components
- Ensures true concentric machining
- Improves surface finish & dimensional control
- Reduces rejection and rework
- Ideal for high-volume and precision machining