Pawl selection mechanism for ratchet tools

A ratchet tool comprising:

• a head having a hole defined therethrough and a recess defined in an inner periphery of the hole, a slot defined in a side of the head and communicating with the recess, two positioning recesses defined in an inner periphery of the slot;
• an engaging member rotatably received in the hole of the head and having a toothed outer periphery;
• a pawl movably received in the recess and having a toothed surface defined in a first side of the pawl, the toothed surface matched with the toothed outer periphery of the engaging member, two concavities defined in a second side of the pawl, and
• a selection member movably inserted in the slot and a straight through hole defined through the selection member, a bead, a spring and a biasing piece received in the through hole, the bead and the biasing piece respectively biased by two ends of the spring, the bead engaged with one of the two positioning recesses in the slot and the biasing piece engaged with one of the two concavities of the pawl, the selection member having an elongated groove and a retaining piece inserted in the elongated groove, the retaining piece having a bar which contacts and retains the biasing piece from being disengaged from the through hole, a top plate connected to the selection member and two knurl portions defined in a surface of the top plate.