夾頭轉接器，2-1/4"-8 螺紋，直徑 6 英吋

The blank face gave me plenty of room to drill my own bolt pattern for a 3-jaw, and the 6" diameter sits solidly on the spindle. Took an afternoon of setup, but the threads engaged smoothly and it's been running true ever since.

I machined this adapter for my 4-jaw chuck and the heavy 6" diameter gave plenty of grip. The threads cut cleanly with a steady hand, and now my work runs true.

The lack of pre-drilled holes was actually a bonus for me—I set it up on my own lathe and machined it to fit my 4-jaw perfectly, and the 6" diameter gives plenty of grip without any wobble. Took about an hour of careful work, but the solid feel on the spindle thread is exactly what I needed.