Hermle B 300 U

The Hermle B 300 U is a compact 5-axis universal machining center built on Hermle's trunnion-table architecture — distinct from the modified gantry design used in the C-series machines. Where the C-series moves the gantry in X and Y while the workpiece remains stationary, the B 300 U uses a tilting rotary table (A and C axes) that positions the workpiece while the spindle moves in Z only. This results in a more compact footprint and faster rotary axis dynamics, making the B 300 U well-suited to smaller, lighter workpieces that benefit from agile table motion during simultaneous 5-axis contouring.

Axis travels measure 650 x 560 x 470 mm (X/Y/Z), and the tilting rotary table accepts workpieces up to 600 mm in diameter and 300 mm tall, with a maximum table load of 300 kg. The A-axis swivels -130° to +20° and the C-axis provides full 360° continuous rotation. This combination gives access to five sides of a workpiece and enables simultaneous 5-axis contouring for complex impellers, dental implant abutments, turbine blades, and orthopedic components. The compact rotary table and direct-drive torque motors on both rotary axes deliver high acceleration and positioning accuracy, with rotary axis positioning accuracy specified at ±5 arc seconds.

Spindle options for the B 300 U include a 15,000 rpm HSK-A63 unit as standard, with 18,000 and 20,000 rpm high-speed variants available for aluminum-intensive work. Continuous spindle power is 17 kW with 100 Nm of torque — appropriate for the workpiece size class this machine addresses. The standard tool magazine holds 36 tools, expandable to 68 with an optional extension module. Tool change time is approximately 5 seconds chip-to-chip. The Heidenhain TNC7 control (on current GEN2 models) provides TCPM (tool center point management), kinematic calibration, and Dynamic Precision features that compensate for dynamic errors during high-speed contouring.

Hermle's mineral cast machine bed is a key differentiator at this size class. Polymer concrete has roughly 6-8x better vibration damping than grey cast iron, which directly reduces surface roughness on finish passes and extends tool life on difficult materials. The B 300 U's mineral cast base combines with the direct-drive rotary axes to produce the geometric accuracy characteristic of Hermle machines — volumetric accuracy typically achieves ±0.015 mm in 5-axis production conditions. This level of accuracy is why Hermle machines are found in dental labs, medical device factories, and aerospace precision component shops.

Pricing for the B 300 U typically ranges from $280,000 to $420,000 depending on spindle speed, tool magazine size, automation options, and probing. Hermle offers the RS 05-2 robotic handling system and HS Flex pallet automation for the B-series, enabling unattended production on small, high-value parts. Competitive alternatives include the DMG Mori DMU 50, Mazak Variaxis i-500, and GF Machining Mikron MILL P 500 U. The B 300 U commands a premium over these alternatives, justified by its mineral cast construction, rotary axis accuracy, and Hermle's reputation for long-term geometric stability.