'P' Type Torque Wrenches are designed for the production environment where they will be set and then dedicated to a particular application. There is no scale, the wrench must be set against a torque testing device such as Norbar's Professional Torque Tester. The ratchets on these models are robustly engineered for strength and durability. The strength and high wear resistance comes from a coarse tooth pattern while a principle of offset ratchet pawls gives a narrow engagement angle. The square drive is not only a robust design but allows the wrench to be used for torque control in both the clockwise and anti clockwise directions, by removing the square and re-inserting on the other side of the ratchet head.