USED DMG MORI NVG-7LH

The DMG MORI NVG-7LH is a specialized CNC vertical deep-hole grinding machine designed for high-precision internal grinding of long cylindrical components with large depth-to-diameter ratios. Developed under DMG MORI in collaboration with Taiyo Koki, this model is optimized for deep bore machining where conventional grinding machines cannot maintain stability or accuracy. It is widely used in industries such as construction equipment, hydraulic systems, energy machinery, and heavy engineering components like large cylinders and hydraulic breaker housings.

The NVG-7LH is designed for large workpieces with a swing diameter of 750 mm and a maximum grinding diameter of 750 mm. It supports a maximum workpiece height of 1,100 mm and a grinding length of up to 1,000 mm. This makes it suitable for deep-hole applications where long internal surfaces must be ground with high precision and consistency. The work spindle operates at speeds up to 200 rpm, while the grinding spindle reaches up to 6,000 rpm, ensuring stable and controlled material removal even in deep internal bores.

A key advantage of the NVG-7LH is its vertical machine structure, which improves setup efficiency and reduces workpiece deformation by using gravity-assisted positioning. This allows easier centering of long and heavy parts while improving roundness, cylindricity, and surface finish quality. The machine also ensures efficient coolant delivery directly to the grinding zone, which is critical for deep-hole machining stability.

The NVG-7LH is equipped with high-precision feedback systems (0.1 µm level control) to compensate for thermal and mechanical deviations during long grinding cycles. It also incorporates heat isolation design features to maintain machining accuracy over extended operations. Overall, the NVG-7LH is a highly specialized deep-hole grinding solution built for large, heavy-duty cylindrical components requiring extreme internal precision.

DMG MORI NVG-7LH SPECIFICATIONS

WHY BUY USED DMG MORI NVG-7LH

Buying a used DMG MORI NVG-7LH is a strategic choice for manufacturers dealing with large deep-hole components but looking to reduce capital expenditure. One of the biggest advantages is cost savings. New deep-hole grinding machines are extremely expensive due to their specialized spindle systems, large structural design, and precision control technology, while used machines can deliver similar capability at a significantly lower investment.

Another key advantage is durability. Machines produced by DMG MORI are built for heavy industrial use, and the NVG-7LH is specifically designed for long-duration, low-force grinding applications. Because grinding forces are relatively low compared to cutting processes, structural wear is reduced, allowing older machines to remain accurate and productive when properly maintained.

Cutting time (machine hours) is especially important for this model. Machines with lower operating hours typically offer better spindle condition, improved axis accuracy, and longer remaining service life. However, even high-hour machines can still be a good investment if they have undergone proper refurbishment such as spindle rebuilding, guideway servicing, or control system upgrades. Maintenance history is often more important than manufacturing year.

Another advantage is availability. Used NVG-7LH machines are typically easier and faster to acquire than new machines, which often require long production and customization lead times due to their specialized nature. Many used units also include fixtures, tooling, or automation systems, reducing setup cost and accelerating production readiness.

Depreciation also benefits buyers significantly. High-end deep-hole grinding machines lose value over time while retaining their core functional capability. This makes the NVG-7LH an attractive option for companies expanding into large-cylinder internal grinding without committing to extremely high capital investment.

HOW MUCH DOES A USED DMG MORI NVG-7LH COST?

The cost of a used DMG MORI NVG-7LH varies depending on manufacturing year, condition, cutting hours, spindle wear, and included tooling or automation features. As a highly specialized deep-hole vertical grinding machine, it typically falls into the premium segment of the used CNC grinding market due to its size and application-specific design.

For machines manufactured before 2000, prices generally range from $60,000 to $150,000. These units often have higher cutting hours and may require refurbishment such as spindle rebuilding, axis recalibration, or control system upgrades. However, they can still be suitable for lower production volumes if properly maintained and rebuilt.

Machines from the 2000–2010 period typically range between $140,000 and $300,000. These versions often include improved CNC controls and better thermal stability systems. At this stage, cutting time becomes a major pricing factor—machines with lower hours or documented maintenance history command significantly higher value due to improved accuracy and reliability.

For newer machines manufactured between 2010 and 2025, prices can range from $300,000 to $650,000 or more, depending on configuration, automation level, and condition. Machines with low operating hours, upgraded feedback systems, or integrated measurement technology typically command a premium, especially in heavy-duty industrial environments.

Cutting time is one of the most important pricing drivers. Lower-hour machines offer better spindle life and reduced maintenance risk, while high-hour machines may require additional investment in refurbishment or recalibration. Buyers should also consider installation complexity, tooling, and logistics costs, which are significant for machines of this size. Overall, the NVG-7LH represents a high-value but specialized investment for deep-hole precision grinding applications in heavy industry.