Okuma GP-67N
Key Specifications
X Travel
Z Travel
max grinding diameter
distance between centers
grinding wheel size
wheel speed max
Overview
The Okuma GP-67N is the largest machine in Okuma's N series universal cylindrical grinders, featuring a 600 mm (23.6 in) maximum grinding diameter with 1,500 mm (59.1 in) between centers. This is Okuma's flagship universal grinder, designed for the largest and heaviest shaft-type components found in power generation, marine, mining, and heavy industrial applications. When a workpiece is too large for the GP-57N, this is where Okuma shops go.
The swivel wheelhead with programmable angular positioning handles OD cylindrical grinding, shoulder grinding, angular plunge grinding, and taper grinding. The grinding wheel is 510 x 50 mm (20.1 x 2.0 in) with a maximum peripheral speed of 45 m/s (8,858 sfm). The wheel spindle uses heavy-duty hydrodynamic bearings sized for the larger grinding forces encountered on 600 mm diameter workpieces.
The X-axis (infeed) travel is 340 mm (13.39 in) with a minimum feed increment of 0.0001 mm (0.000004 in). The Z-axis (traverse) travel is 1,550 mm (61.02 in). Rapid traverse rates are 10 m/min (394 ipm) on X and 12 m/min (472 ipm) on Z. The headstock provides workpiece rotation from 10 to 300 RPM with an MT6 center, reflecting the larger center bore needed for heavy workpiece support.
The 1,500 mm between centers accommodates the longest shaft-type workpieces in Okuma's grinding lineup. Steady rest support at multiple positions along the table is essential for grinding long shafts, and the GP-67N's table length accommodates several steady rest locations. The programmable wheelhead swivel enables automatic angle changes between different grinding features along the shaft length.
Machine weight is approximately 13,000 kg (28,660 lb). Floor space runs approximately 6,200 x 3,000 mm (244 x 118 in). New pricing typically ranges from $350,000-$500,000. The GP-67N competes with large Studer, WaldrichSiegen, and Schaudt grinders for heavy-duty universal cylindrical grinding applications.
Full Specifications
| Parameter | Value |
|---|---|
| Max Grinding Diameter | 600 mm (23.6 in) |
| Distance Between Centers | 2,150, 2,650, or 3,150 |
| Grinding Wheel Size | 510 x 50 mm (20.1 x 2.0 in) |
| Wheel Speed Max | 45 m/s (8,858 sfm) |
| Wheelhead Swivel | Programmable angular positioning |
| X-Axis Travel | 340 mm (13.39 in) |
| Z-Axis Travel | 1,550 mm (61.02 in) |
| Min Feed Increment | 0.0001 mm (0.000004 in) |
| Rapid Traverse X | 10 m/min (394 ipm) |
| Rapid Traverse Z | 12 m/min (472 ipm) |
| Workhead Speed | 10 - 300 RPM |
| Workhead Center | MT6 |
| Id Grinding Spindle | Optional attachment |
| Machine Weight | 13,000 kg (28,660 lb) |
| Floor Space | 6,200 x 3,000 mm (244 x 118 in) |
| CNC Control | Okuma OSP-P300G |
| Max Grinding Dia | Ø650 |
| Grinding Wheel Odxid | Ø760 × Ø304.8 |
| Max Grinding Wheel Width | 130 |
| Rapid Traversex | 12 |
| Rapid Traversez | 10 |
| Wheel Spindle Motor | 15 |
| Okuma Global Repair Center | Charlotte, North Carolina |
| Inches | Metric |
Specifications sourced from okuma.com — verified 2026-03-28
Strengths & Limitations
Strengths
- 600 mm grinding diameter and 1,500 mm between centers represent the largest capacity in Okuma's universal grinding lineup, handling workpieces no other N-series machine can accommodate
- 340 mm X-axis travel provides the extended infeed stroke needed for approaching and grinding the largest-diameter workpieces with proper clearance
- 1,550 mm Z-axis traverse enables full-length traverse grinding and multi-position plunge grinding across the entire length of long heavy shafts
- MT6 headstock center and heavy-duty tailstock support the weight and driving force requirements of large, heavy workpieces
- 13,000 kg machine mass provides the vibration damping essential for maintaining surface finish quality on large-diameter heavy cuts
- Programmable swivel wheelhead enables complex grinding profiles including OD, shoulders, tapers, and angular features in a single setup on large components
Limitations
- 6,200 x 3,000 mm footprint requires a large dedicated machine bay with overhead crane access for loading heavy workpieces
- 13,000 kg machine weight demands engineered foundation work, potentially including isolated foundations in vibration-sensitive grinding departments
- Starting price of $350,000 and fully equipped configurations approaching $500,000 require consistent large-part work to justify the investment
- 300 RPM maximum headstock speed is appropriate for large diameters but limits surface speed options on smaller features ground on the same workpiece
- Heavy workpiece handling requires dedicated lifting equipment and trained personnel, adding operational overhead beyond the machine itself
Best For
Frequently Asked Questions
01
New pricing ranges from $350,000-$500,000 depending on wheelhead configuration, ID grinding attachment, in-process gauging, steady rest packages, and specialized workpiece driving systems. Used GP-67N machines are rare due to low production volumes and the specialized nature of large-diameter universal grinding.
02
The GP-67N offers 600 mm vs 500 mm grinding diameter, 1,500 mm vs 1,000 mm between centers, more X-axis travel (340 mm vs 305 mm), and MT6 vs MT5 centers. It weighs 13,000 kg vs 9,000 kg. The GP-67N targets the largest workpieces in heavy industry that exceed the GP-57N's capacity. Choose based on your maximum workpiece size.
03
At 13,000 kg, the GP-67N requires a reinforced concrete foundation engineered for point loads at each leveling pad. For precision grinding, an isolated foundation that decouples the machine from building vibrations is recommended. Foundation preparation costs typically run $15,000-$25,000 depending on existing floor conditions.
04
Yes, within its 600 mm diameter and 1,500 mm length limits. The machine handles printing rolls, converting rolls, and industrial processing rolls that need precision cylindrical profiles. For larger rolls exceeding these limits, dedicated roll grinders are needed. The universal swivel wheelhead is particularly useful for grinding rolls with crowned profiles and end journals.
05
For workpieces approaching the machine's 600 mm diameter and 1,500 mm length capacity, overhead crane loading is essential. These workpieces can weigh hundreds of kilograms and cannot be safely handled manually. Plan for at least a 2-ton crane with adequate hook height above the machine's center height.
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