A device for holding a workpiece, the device comprising, in one form, a base and a jaw member, wherein the jaw member includes a detachable jaw plate. The jaw member can further include a lock assembly which can attach or affix the jaw plate to the jaw member. In at least one embodiment, the lock assembly can include a cam, or lock, configured to pull the jaw plate toward the jaw member and/or secure the jaw plate against the jaw member. In certain embodiments, the lock assembly can include a slide which can be moved by an actuator such that the slide can engage the jaw plate and move the jaw plate into position. In at least one such embodiment, the slide can pull the jaw plate against the jaw member and, in addition, pull the jaw plate downwardly against a workpiece support surface.

A holding apparatus for holding a workpiece, which has a round and/or tubular cross section and is to be machined, in such a way that, in the held state, the workpiece can be rotated in relation to the holding apparatus, having at least two clamping arms, which are mounted in a pivotable manner on a base part and by means of which a clamping force can be exerted onto the workpiece, and having an adjustment mechanism for the clamping arms. Provision is made for the adjustment mechanism to have at least two drivers which are guided in a straight line, it being possible for the clamping arms to be pivoted or the clamping arms being pivoted toward one another by virtue of the movement of the drivers, wherein the drivers are arranged in a manner situated one behind the other as seen transversely in relation to the direction of movement of the drivers. In addition or as an alternative, provision is made for the adjustment mechanism to have a threaded spindle which can be manually operated and/or can be operated by an auxiliary force and which is in detachable threaded engagement with a threaded part, wherein the threaded part is, in the axial direction of the threaded spindle, held fixed in position in relation to the base part on a component of the holding apparatus, in particular on the base part. The invention further comprises an apparatus for machining a workpiece which has a round and/or tubular cross section, the apparatus containing a holding apparatus for the workpiece.

A stop device having a L shaped mounting bracket secured to a machine vise by a mounting bracket screw, a stop arm having an elongated slot extended within the stop arm and running in a parallel direction to a length of the stop arm, a pivot clamp and pivot clamp screw connected to the elongated slot and attaching the stop arm to the mounting bracket along a length side of a machine vise, the stop arm moveable in both an Y and Z direction and lockable by the pivot clamp, a fixed jaw located at the second end of the stop arm and a stop clamp attached to the second end of the stop arm by stop clamp screw, the stop clamp including an adjustable jaw facing the fixed jaw of the stop arm with the stop clamp screw enabling changes to a distance between the jaws to allow the jaws to hold and support a portion of a stop rod having varying shapes and sizes in a fixed, deform-free condition therebetween.

A clamp release mechanism is provided. The clamp includes a body, a shaft slideably coupled to the body, a fixed jaw, and a moveable jaw coupled to the shaft. A locking component actuates between a locked position and an unlocked position. When in the locked position, the locking component biases the shaft to remain stationary with respect to the body. The clamp includes a securing component pivotally coupled to the locking component, and a biasing element that biases the securing components towards the shaft.