These look like a thread chaser. The O.D. Is 1.18 inches with 12 threads per inch. The shaft is 3/4” dia., 16 TPI. The problem would be how to reverse for removal. Most taps and chasers I have seen have a square drive end.

The complete kit includes:

2 – 1-1/8“ 12 TPI chasers 6” long with ¾” dia 16 TPI threads on the other end

2 – 1-1/8” 12 TPI nuts,

1 - ¾” diameter by 10” long rod 16 TPI

1 - 3/4” dia 16 TPI Nut\

5 bs. Shipping USPS

QZ 1708 01