A wire reel is detachably provided in a housing chamber of a binding machine body which binds a reinforcing bar. The wire reel includes a cylindrical hub portion which winds a wire, and a pair of parallel flanges overhanging outward from both external peripheral ends of the hub portions. A side wall inside the hub portion is formed of light-transmitting portions which allow the light from a transmissive photosensor provided in the binding machine body to be transmitted therethrough.

An apparatus for dispensing tie wire having a housing with a main housing part and a cover part. The cover part is releasably joined with the main housing part to thereby place the main housing part and cover part in an assembled relationship wherein a wrapped supply of tie wire is blocked in an operative position within the housing. A latch component is selectively movable between latched and unlatched positions. In the latched position the main housing part and cover part are maintained in the assembled relationship. A latch control is selectively changeable between first and second states, and: i) with the latch control in the first state, the latch control blocks the latch component from moving from the latched position into the unlatched position; and ii) with the latch control in the second state, the latch component can be moved from the latched position into the unlatched position.