WOOD 4 SPUR DRIVE CENTRE 1"X8TPI FEMALETHREAD WITH TURNING DOWEL HOLE- HIGHSPEED WILL SUIT 1" X 8TPI MALE MOUNTSWood 4 Spur Drive Centre features a 1"x10TPI female thread and includes a turning dowel hole. Designed for high-speed applications, it is compatible with 1" x 10TPI male mounts.