OKK VB840

The OKK VP-600 is a compact precision VMC in the 600 mm X-travel class, optimized for high-accuracy die and mold work with a focus on spindle speed and surface finish quality. The VB840 scales up to 840 mm X-travel with a heavier structural design and higher table payload (1,000 kg vs approximately 500 kg on the VP-600), making it the right choice for larger workpieces and heavier cutting. The VP-600 is often preferred for precision mold inserts and small-to-medium cavity work; the VB840 is the choice when mold base size or part weight exceeds the VP-600's capacity.

Yes. The VB840's structural rigidity, box-way damping, and precision spindle make it well-suited for hard milling of tool steel in the 55–62 HRC range with appropriate tooling. The optional 20,000 RPM high-speed spindle is particularly effective for hard milling with small-diameter ball-nose carbide or CBN tools at high surface speeds. Key requirements for successful hard milling include rigid workholding, short tool overhangs, fine surface finish carbide tooling with appropriate coatings (TiAlN, AlCrN), and 70 bar through-spindle coolant or minimum quantity lubrication (MQL) depending on the specific material and tool combination.

Yes. Heidenhain iTNC 640 and the newer TNC 7 are available as alternatives to the standard Fanuc 31i-B. The Heidenhain option is most commonly specified by European mold shops and high-speed machining specialists who prefer Heidenhain's surface finish optimization (AFC — Adaptive Feed Control, DCM — Dynamic Collision Monitoring) and the programming environment for complex 3D surface programs. Heidenhain's Advanced Surface Quality (ASQ) function is particularly valued for mold cavity finishing where minimizing surface irregularities from axis reversals is critical.

The OKK VB840 comes equipped with a 70 bar through-spindle coolant system as standard. This pressure level is appropriate for the machine's primary applications in steel, cast iron, and titanium machining where chip evacuation from deep features and heat management at the cutting tip are critical. Minimum quantity lubrication (MQL) is also available as an alternative for applications such as hardened steel finishing where flood coolant can cause thermal shock to the workpiece or tooling, or for environmental reasons. The spindle design accommodates both TSC and MQL on the same machine with appropriate tool holders.

OKK designs for long-term accuracy retention through heavy cast iron structure (minimal thermal distortion and dimensional creep over time), precision Hirth or angular contact bearing assemblies, and box-way geometry that maintains its clearance characteristics through controlled lubrication rather than wear. OKK's service network provides periodic accuracy verification and realignment services at planned intervals. The company provides laser interferometer test procedures for field verification of all axis positioning specifications, enabling buyers to document machine capability at any point in the machine's service life.