fastspænding

Fastspænding is the process of securing a workpiece firmly in a fixed position relative to a machine or reference surface to enable accurate and repeatable machining or measurement. The goal is to resist cutting forces, vibration, and thermal expansion during operations such as milling, turning, drilling, grinding, welding, and metrology. Proper fastspænding improves part accuracy, repeatability, surface finish, tool life, and safety, while reducing setup time and handling errors.

Typical methods and devices include vices, clamps, fixtures, parallels, collets, and magnetic or hydraulic clamps. Workholding systems are chosen for rigidity, repeatability, ease of use, and accessibility of the work zone. In milling and drilling, workpieces are clamped to the machine table with vises and fixture plates; in turning, chucks or collets hold the part in the spindle. Modular fixturing supports fast changes for different parts.

Key design considerations include achieving uniform clamping force without deforming the workpiece, distributing load to prevent tipping, and ensuring tool access is not impeded. Thermal effects, fixture tolerances, and repeated clamping cycles must be accounted for. The choice of method influences cycle time, accuracy, surface quality, and overall production cost.

Safety and maintenance are important, since loose or poorly secured parts can eject during machining or cause tool damage. Regular inspection of clamps and surfaces, along with standardized setup procedures, helps sustain performance. In modern manufacturing, modular fixturing and quick-change systems are common to improve repeatability and throughput.