Thanks everyone. It is threaded. I looked it up on the internet. San Ou B10. It's a B10 thread per Amazon. I tried vice grips and still can't loosen it in either direction.
https://www.amazon.com/Hitommy-0-6-6mm-Electric-Thread-Adapter/dp/B07FTGY59T
I ordered this about 2" chuck yesterday. I can mount it in the jaws of the chuck I can't get off. The reason I bought this chuck as it will hold a larger diameter piece to carve/sand.
https://www.amazon.com/gp/product/B09BQFR7Y6?ref=ppx_pt2_dt_b_prod_image&th=1
https://www.amazon.com/Hitommy-0-6-6mm-Electric-Thread-Adapter/dp/B07FTGY59T
I ordered this about 2" chuck yesterday. I can mount it in the jaws of the chuck I can't get off. The reason I bought this chuck as it will hold a larger diameter piece to carve/sand.
https://www.amazon.com/gp/product/B09BQFR7Y6?ref=ppx_pt2_dt_b_prod_image&th=1