Hardinge Style-S master collets use interchangeable pads that can be changed without removing the master collet from the spindle, thus reducing change-over time. When loading bars, the shoulder of the pad locates against the front of the groove in the master collet. There are no set screws or clamps to be damaged or loosened. When a part is machined, the working forces are against the rear shoulder of the pad that is located against the rear shoulder of the groove in the master collet. The clamp that holds the pads in the collet floats longitudinally, so no pressure is on the clamp, the company says. There are no holes in the OD of the master or on the ID of the pads, resulting in maximum bearing on the workpiece and the spindle collet seat. Hardened pads are available in round, hex and square shapes with smooth or serrated order holes. They can also be custom-made for extruded stock.
The company also offers Style-B feed fingers and pads designed for high-production bar machining. No screws or pins are necessary to hold the pads in place. According to the company, pads cannot come loose, and they offer full bearing on the barstock. They are available in round, hex, square and custom shapes in a variety of materials and sizes. The master feed fingers are made from proprietary material and are spring-tempered to hold tension. Custom master feed fingers can be made for extremely light grip or heavier grip for non-standard applications. Pads are available in different materials depending on the barstock used. Hardened steel pads are used for hot-rolled and cold-drawn stock and are designed for long wear and minimized scoring of the steel. Nickel cast iron pads are for use on brass, aluminum, polished or plated bars and special-finish drawn bars to eliminate scoring of stock. Bronze pads are for ground drill rod, ground bars and the materials previously listed for the nickel cast iron pads (excluding brass) to eliminate scoring of stock.