Challenge
The team needed to hold a small internal diameter, maintain stringent geometry, and run underwater without sacrificing throughput:
- Grip a 0.302" I.D. to 0.75" depth , locate on a face, and hold ≤ 4 µm concentricity during wire EDM.
- Operate fully submerged in deionized water , where standard alloy-steel chucks would rust in days.
- Integrate actuation with the EDM rotary table for automated clamping and release.
- Deliver repeatable accuracy on a slender, deep I.D. grip —already a major challenge in dry conditions.
Solution
We built a custom internal-grip collet chuck that pairs sub-micron alignment with EDM-ready materials and actuation:
- Deep-reach, pull-back collet : engages 0.75" into the bore; pull-back action seats the face positively for repeatable location.
- Micron-class performance : chuck repeatability to ≈ 2 µm , supporting the ≤ 4 µm concentricity requirement
- All-stainless construction : every component is stainless steel; critical elements are heat-treated to 58–63 HRC , others to 48–52 HRC , with select parts left soft as required for function.
- Rotary-table integration : a rear port couples to a manifold adapter for spring clamp / air release actuation, cleanly interfacing with the EDM rotary.
Outcome
The result is a production-ready, underwater-capable chuck that protects accuracy and uptime:
- Corrosion resistance: for submerged EDM and engineered to last for years in deionized water environments.
- Reliable seating and geometry : pull-back action and face location maintain micron-level alignment throughout cutting.
- Hands-off operation : seamless rotary-table actuation supports automated, repeatable clamping.