Frezen

Frezen, or milling, is a subtractive manufacturing process in which material is removed from a workpiece by rotating cutting tools called milling cutters. The workpiece is typically clamped on a milling machine or CNC milling center, and the cutter generates features by moving in multiple axes relative to the workpiece.

Common milling operations include face milling, end milling, slot milling, and profile milling. Milling machines range from manual horizontal or vertical mills to CNC milling centers capable of complex 3D contouring. Feature sizes can range from small grooves to large pockets.

Cutting tools used in frezen are usually solid carbide or high-speed steel end mills, ball-nose cutters, and specialty form tools. Tool geometry, material, and coating influence performance. Spindle speed, feed rate, depth of cut, and step over determine material removal rate and surface quality.

Frezen can be performed on many materials, including metals (aluminum, steel, titanium), plastics, and wood. Tolerances depend on machine capability, tool geometry, and rigidity; typical CNC milling tolerances range from ±0.01 to ±0.1 mm for finished parts, with tighter tolerances achievable under controlled conditions.

Key considerations include tool deflection, chatter, chip evacuation, and heat buildup. Climb milling and conventional milling are two approaches with different effects on tool life and surface finish. Coolants or cutting oils are often used to improve cooling and chip control.

Frezen is widely used in manufacturing, prototyping, aerospace, automotive, mold making, and consumer electronics. It evolved from rigid early milling machines to modern CNC systems that enable high precision, repeatability, and automation.