Clamping equipment

Mechanical clamping equipment transmits clamping forces through direct force application. Typical versions include power clamping blocks, chucks, clamping claws, and hold-down devices.

Vices hold workpieces between a fixed and a movable jaw. They are among the most commonly used types of clamping equipment in metalworking and are available in clamping widths ranging from a few millimeters to over 500 mm. Machine vises for CNC applications enable high repeatability during clamping.

Clamping claws are mounted directly on the machine table and are suitable for workpieces where circumferential clamping is not possible. Hold-down devices secure the workpiece from above against a defined support surface and are used when lateral clamping points would restrict tool access.

Pneumatic and hydraulic clamping equipment actuates the clamping elements using pressurized media. The advantage over manual operation lies in uniform, reproducible clamping forces and significantly shorter set-up times.

Hydraulic clamping equipment generates high clamping forces—typically up to 50 kN at a system pressure of 400 bar—in a compact shape and is particularly well-suited for heavy-duty machining. Pneumatic clamping equipment is suitable for fast clamping cycles with lower clamping forces, such as those encountered in automated manufacturing processes.

Magnetic clamping plates hold ferromagnetic workpieces in place using magnetic force. Since no lateral clamping elements are required, the entire surface of the workpiece is accessible for machining. Both permanent magnet and electromagnet versions are available.

Vacuum-based clamping equipment generates holding force through vacuum. This method allows for the damage-free clamping of workpieces made of wood, glass, plastics, or metal without the need for mechanical clamping points. It is particularly well-suited for large-surface, thin-walled, or delicate workpieces where mechanical clamping equipment would cause warping or surface damage.

Clamping equipment must safely absorb the forces generated during the machining process and hold the workpiece in its defined position.

• Clamping force and stiffness: The applied clamping force must be sufficient to prevent displacement of the workpiece even under maximum process forces. Depending on the machining operation, these forces are not absorbed exclusively by the clamping force but also by form-fitting elements such as stops. At the same time, the clamping force must not deform the workpiece.
• Repeatability: In series production, it is crucial that each workpiece is clamped in exactly the same position. Tight positioning tolerances are a prerequisite for consistent machining quality.
• Accessibility: The clamping equipment must restrict the tool path as little as possible. In multi-side or 5-axis machining, clamping elements must be arranged so that all relevant areas are accessible without re-clamping.
• Workpiece Protection: Clamping equipment must protect the workpiece surface. For sensitive materials, versions of clamping equipment that prevent pressure marks or clamping technologies that apply force over a wide area—such as vacuum clamping technology—are suitable.
• Ease of Setup: Short set-up times lower operating costs. Clamping equipment with quick-clamping functions or standardized interfaces significantly reduce the effort required for workpiece changes.