A pipe threader comprises a housing and a drive assembly including a motor and an output gear having a first plurality of teeth. A die holder defines a rotational axis and includes a gear member including an outer circumference with a second plurality of teeth engaged with the output gear. The gear member includes an inner circumference with a key recess. A lock ring is rotatable relative to the gear member and including a contact surface. A key is arranged in the key recess and a biasing member in the key recess and biasing the key toward the rotational axis. The lock ring is movable between a locked position, in which the contact surface inhibits the key from moving away from the rotational axis, and an unlocked position, in which the key is movable away from the rotational axis in response to insertion of a die into the die holder.