Mazda RX-8 Manual page 1647

Block joint type
1. Temporarily tighten the joint bolt by hand.
2. Connect the block joint type pipes by grasping the female side of the block with pliers or similar tool
and holding firmly, and then tighten the connection bolt or nut with a torque wrench.
Notes:
(w) RX-8 - HVAC
Page 18