Chuck Style is my term because they look a bit like a drill chuck. Best identified visually because search terms are similar to the others. This is a clever design giving you multiple drive options by using a spanner on the outside hexagonal shaft or sticking a square drive ratchet or impact wrench into the square opening in the centre.
- Remove headless shafts (studs).
- Remove protruding snapped shafts.
- Can be used with impact wrenches.