A crimp tool comprising: a tool body comprising: a first handle; a second handle, pivotally connected with the first handle; a head, connected with the first handle; a driving element, connected with and actuated by the second handle, the direction of motion of the driving element defining a first axis; and a cassette for machining a connector, comprising: a cassette body being detachably disposed in an opening of the head of the tool body, the cassette body having a machining opening therein for receiving the connector, the machining opening responsive to the driving element when the cassette is disposed in the tool body for machining the connector; and characterized in that the cassette further comprises: a machining block, slidably disposed in the cassette body, the machining block having an engagement element for being detachably engaged with the driving element of the tool body wherein through the engagement element, the driving element drives the machining block to slide along the first axis to move toward or away from the machining opening; the cassette body comprising a second connecting structure disposed thereon for securing the cassette body within the opening of the head of the tool body; wherein the second connecting structure provides releasable engagement with the first connecting structure when disposed in the opening of the head of the tool body to secure the cassette body within the head of the tool body, wherein the second connecting structure comprises a stopper, a first hook and a second hook, wherein the stopper is located to abut against one of a first surface and a second surface of the head of the tool body along a second axis perpendicular to the first axis when the cassette body is disposed in the opening of the head of the tool body and wherein the first hook and the second hook are respectively disposed at the two lateral sides of the cassette body, the first hook and the second hook extending away from the stopper in a direction substantially parallel to the second axis so as to engage with the other of the first surface and the second surface of the head of the tool body. a first handle; a second handle, pivotally connected with the first handle; a head, connected with the first handle; a driving element, connected with and actuated by the second handle, the direction of motion of the driving element defining a first axis; and a cassette for machining a connector, comprising: a cassette body being detachably disposed in an opening of the head of the tool body, the cassette body having a machining opening therein for receiving the connector, the machining opening responsive to the driving element when the cassette is disposed in the tool body for machining the connector; and characterized in that the cassette further comprises: a machining block, slidably disposed in the cassette body, the machining block having an engagement element for being detachably engaged with the driving element of the tool body wherein through the engagement element, the driving element drives the machining block to slide along the first axis to move toward or away from the machining opening; the cassette body comprising a second connecting structure disposed thereon for securing the cassette body within the opening of the head of the tool body; wherein the second connecting structure provides releasable engagement with the first connecting structure when disposed in the opening of the head of the tool body to secure the cassette body within the head of the tool body, wherein the second connecting structure comprises a stopper, a first hook and a second hook, wherein the stopper is located to abut against one of a first surface and a second surface of the head of the tool body along a second axis perpendicular to the first axis when the cassette body is disposed in the opening of the head of the tool body and wherein the first hook and the second hook are respectively disposed at the two lateral sides of the cassette body, the first hook and the second hook extending away from the stopper in a direction substantially parallel to the second axis so as to engage with the other of the first surface and the second surface of the head of the tool body. a machining block, slidably disposed in the cassette body, the machining block having an engagement element for being detachably engaged with the driving element of the tool body wherein through the engagement element, the driving element drives the machining block to slide along the first axis to move toward or away from the machining opening; the cassette body comprising a second connecting structure disposed thereon for securing the cassette body within the opening of the head of the tool body; wherein the second connecting structure provides releasable engagement with the first connecting structure when disposed in the opening of the head of the tool body to secure the cassette body within the head of the tool body, wherein the second connecting structure comprises a stopper, a first hook and a second hook, wherein the stopper is located to abut against one of a first surface and a second surface of the head of the tool body along a second axis perpendicular to the first axis when the cassette body is disposed in the opening of the head of the tool body and wherein the first hook and the second hook are respectively disposed at the two lateral sides of the cassette body, the first hook and the second hook extending away from the stopper in a direction substantially parallel to the second axis so as to engage with the other of the first surface and the second surface of the head of the tool body.