Milling Chucks come in 3 and 2 jaw configurations.

MicroCentric

Available in 3, 4, 5, and 6 in. sizes for OD and ID clamping applications, manually actuated Production Milling Chucks integrate with tombstones and pallets for machining centers, milling machines, and grinders. They are clamped and unclamped on top face, enabling more chucks to be ganged together. Chucks feature 2 stage clamping; fast initial jaw stroke for large opening and primary stage to provide high clamping force