Okuma GP-57N

Est. $280,000 - $400,000 Specs verified 2026-10-03 · okuma.com Updated 2026-10-03

Image: okuma.com, Okuma

Key Specifications

max grinding diameter

550 mm (21.65 in)

distance between centers

2,150, 2,650, or 3,150 mm (84.65, 104.33, or 124.02 in)

grinding wheel size

760 × 304.8 mm (29.925 × 12 in)

rapid traverse x

12 m/min (472 ipm)

rapid traverse z

10 m/min (394 ipm)

workhead center

MT5

How much does the Okuma GP-57N cost?

Estimated price range

Est.$280,000 - $400,000

Our best estimate for a cnc grinding machine in this class — not a quote from Okuma. Configuration moves it a long way.

Overview

With 550 mm (21.65 in) of grinding diameter, the Okuma GP-57N sits in the middle of Okuma's long-bed cylindrical grinder range and is the size that brings rolls and flanged shafts into reach. Distance between centers is a choice of 2,150, 2,650, or 3,150 mm (84.65, 104.33, or 124.02 in).

What the step up in swing does not bring is more wheel or more motor. The GP-57N grinds with a wheel listed at 760 × 304.8 mm (29.925 × 12 in), 130 mm (5.12 in) wide, on a 15 kW (20 hp) wheel spindle motor, and the GP-47N lists the same motor and wheel width for 400 mm (15.75 in) work. A buyer moving up for capacity should expect the larger machine to cover a bigger part at the same rate of stock removal, not a faster one. On a roll body several times wider than the 130 mm wheel, that means traverse grinding in many overlapping passes, and cycle time grows with both the diameter and the length of the surface.

Positioning moves are quicker across the machine than along it: rapid traverse is 12 m/min (472 ipm) in X against 10 m/min (394 ipm) in Z. The workhead center is MT5. Okuma's headline table for this model does not give a workhead speed range or a weight capacity between centers, and for parts near 550 mm in diameter both figures matter, so ask for them alongside the quotation.

If 550 mm is still short, the GP-67N extends the same layout to 650 mm (25.59 in).

Full Specifications

Parameter	Value
Max Grinding Diameter	550 mm (21.65 in)
Distance Between Centers	2,150, 2,650, or 3,150 mm (84.65, 104.33, or 124.02 in)
Grinding Wheel Size	760 × 304.8 mm (29.925 × 12 in)
Rapid Traverse X	12 m/min (472 ipm)
Rapid Traverse Z	10 m/min (394 ipm)
Workhead Center	MT5
Rapid Traversex	12
Rapid Traversez	10
Wheel Spindle Motor	15 kW (20 hp)
Grinding Wheel Width	130 mm (5.12 in)

Specifications sourced from okuma.com — verified 2026-10-03

Strengths & Limitations

Strengths

550 mm (21.65 in) maximum grinding diameter, against 400 mm (15.75 in) on the GP-47N, with the same choice of beds
Center distances of 2,150, 2,650, or 3,150 mm (84.65, 104.33, or 124.02 in) cover long rolls and shafts
Wheel width of 130 mm (5.12 in) on a 760 × 304.8 mm (29.925 × 12 in) wheel
X rapid traverse of 12 m/min (472 ipm) keeps wheel retract and approach short between diameters

Limitations

The wheel motor stays at 15 kW (20 hp), the rating the GP-47N carries for smaller work, so stock removal does not scale with the swing
No bed shorter than 2,150 mm (84.65 in) between centers is listed
Z rapid traverse is 10 m/min (394 ipm), modest for repositioning along a 3,150 mm (124.02 in) bed
Workhead speed range and work weight are missing from Okuma's headline table for this model

Best For

Rolls and large shafts up to 550 mm (21.65 in) in diameter Shafts and rolls needing up to 3,150 mm (124.02 in) between centers Flanged shafts whose largest diameter exceeds the 400 mm (15.75 in) of the GP-47N Traverse grinding of long cylindrical surfaces with a 130 mm (5.12 in) wide wheel

Frequently Asked Questions

01 What is the largest part the GP-57N can grind?

The maximum grinding diameter is 550 mm (21.65 in). Length depends on the bed ordered: 2,150, 2,650, or 3,150 mm (84.65, 104.33, or 124.02 in) between centers. Okuma's headline figures do not state a maximum work weight, which on rolls of this size can be the real limit, so ask for it.

02 Does the GP-57N have a bigger wheel motor than the GP-47N?

No. Both list a 15 kW (20 hp) wheel spindle motor and a 130 mm (5.12 in) wheel width. The GP-57N adds swing, 550 mm (21.65 in) against 400 mm (15.75 in) on the GP-47N, without adding grinding power, so larger surfaces simply take longer.

03 How fast are the axes on the GP-57N?

Rapid traverse is 12 m/min (472 ipm) in X and 10 m/min (394 ipm) in Z. The X figure governs how quickly the wheel clears a shoulder or flange; the Z figure governs moves along a bed that can be as long as 3,150 mm (124.02 in) between centers.

04 When should I look at the GP-67N instead?

When any ground diameter, or any flange the wheel has to pass, is larger than 550 mm (21.65 in). The GP-67N raises the maximum grinding diameter to 650 mm (25.59 in) on the same center distances, and its rapid traverse figures are the same as on this model.