Supplied with coolant-through capability, Softsynchro 0 is designed for tap ranges #2-10 and M2-M8, while Softsynchro 4 handles tap ranges 7/6-1 in. and M12-M30. Units are constructed from 2 separate, precision ground sections: body and shank. Patented elastomer springs separate spindle from tap, absorbing excessive axial forces and compensating for small errors in machining process. Torque from spindle is transferred seamlessly to tap via ball bearings riding in precision ground grooves.