JA4-60 Internal Gripping and Indicator Check
A JA4-60 grips a sleeve-shaped part from its bore. The indicator touches the outside diameter while the operator turns the part. The bore provides the gripping datum. The outside surface remains accessible for machining or inspection.
How the grip works
The built-in pneumatic cylinder flexes a metal diaphragm. Its gripping segments move with that small elastic deflection. The grip does not depend on conventional jaws travelling along long slideways. A replaceable diaphragm collet is finished to match the part. External gripping closes onto the outside diameter. Internal gripping expands against the bore.
Choose the gripping direction from the machining datum. Gripping inside a bore leaves the outside diameter accessible. For a slender shaft or thin wall, set the contact length, overhang and clamping force together. After mounting, check the chuck datum first, then the gripped part.
What to check in this setup
- Specify the usable gripping depth inside the bore.
- Seat the end face against its stop.
- Check radial runout at the actual machining diameter.