A gripper or fixture is a critical component within a workpiece handling mechanism that provides secure, repeatable positioning and holding of materials or parts during operations such as machining, assembly, welding, or inspection. It ensures accuracy, safety, and efficiency in automated or manual production lines. Grippers typically use mechanical, pneumatic, hydraulic, or magnetic force to clamp onto a workpiece, while fixtures are custom-designed structures that locate and restrain a workpiece against locating pins, clamps, or vices to prevent movement during processing forces. This directory entry covers generic grippers and fixtures used in machinery and equipment manufacturing, with typical materials including steel, aluminum, and engineering plastics. Key parameters to consider when selecting a gripper or fixture include clamping force (5–50 kN), operating pressure (0.4–0.8 MPa), repeatability (±0.02 mm, per ISO 230-2), positioning accuracy (±0.05 mm, per ISO 230-2), operating temperature (-10 to 60°C), ingress protection (IP54–IP65, per IEC 60529), material (e.g., aluminum alloy 6061-T6 per ASTM B221), weight (2–15 kg), footprint (100×100 to 300×300 mm), and actuation type (pneumatic for fast cycling; hydraulic for high force). These values are reference ranges for directory purposes and must be verified with the legal manufacturer or supplier for the specific model and application. The choice of gripper or fixture depends on the workpiece geometry, material, process forces, and automation level. Proper selection ensures reliable operation, reduces downtime, and maintains product quality. Always confirm model-specific specifications, standards compliance, and suitability for your process with the manufacturer or supplier before procurement.
Grippers operate by applying force—mechanical, pneumatic, hydraulic, or magnetic—to clamp onto a workpiece, holding it securely during handling or processing. Fixtures, in contrast, are stationary structures that use locating pins, clamps, or vices to position and restrain a workpiece against machining or assembly forces. The working principle involves precise alignment and force application to prevent movement, ensuring repeatable positioning. For pneumatic grippers, compressed air (0.4–0.8 MPa) drives pistons or jaws; hydraulic versions use higher fluid pressure for greater force. Magnetic grippers use electromagnets or permanent magnets. Fixtures are often custom-designed for specific parts, using locating elements to establish a datum and clamps to secure the part. The effectiveness depends on clamping force, rigidity, and accuracy of locating surfaces.
