Okuma GP-GA-34FII

$200,000 - $280,000 Updated 2026-03-13

Key Specifications

X Travel

275 mm (10.83 in)

Z Travel

525 mm (20.67 in)

Rapid Traverse

max grinding diameter

340 mm (13.4 in)

distance between centers

350 / 650 / 1,000 / 1,500

grinding wheel size

510 x 75 mm (20.1 x 3.0 in)

Overview

The Okuma GP-GA-34FII is a CNC cylindrical grinder from Okuma's GA-F series, representing the second generation (FII) with updated controls and improved precision. The GA-F series offers larger grinding capacity than the GA-W models, with the GA-34FII targeting workpieces up to 340 mm (13.4 in) diameter and 500 mm (19.7 in) between centers. This makes it suitable for medium to large diameter shafts, flanges, and precision components.

The grinding wheel is 510 x 75 mm (20.1 x 3.0 in) with a maximum peripheral speed of 45 m/s (8,858 sfm). The larger 510 mm wheel diameter compared to the GA-W series provides more grinding surface and longer wheel life between dressings. The wheel spindle uses hydrodynamic bearings for smooth, vibration-free grinding. The wheelhead can accommodate CBN and superabrasive wheels for high-productivity grinding on hardened steel and difficult materials.

The X-axis (infeed) travel is 275 mm (10.83 in) with a minimum feed increment of 0.0001 mm (0.000004 in). The Z-axis (traverse) travel is 525 mm (20.67 in). Rapid traverse rates are 10 m/min (394 ipm) on X and 15 m/min (591 ipm) on Z. The headstock provides workpiece rotation from 10 to 400 RPM with an MT5 center.

The FII designation brings updated OSP-P300G control with improved gap elimination algorithms, enhanced in-process gauging integration, and faster program execution. The machine includes automatic wheel dressing with diamond dresser, programmable dressing cycles, and coolant management. Table swivel of +/- 6 degrees enables taper grinding.

Machine weight is approximately 6,000 kg (13,228 lb). Floor space runs approximately 3,800 x 2,500 mm (150 x 98 in). New pricing typically ranges from $200,000-$280,000. The GP-GA-34FII competes with Studer S31, Toyoda GE6Pi, and Danobat LG series for medium-diameter precision cylindrical grinding applications.

Full Specifications

Parameter	Value
Max Grinding Diameter	340 mm (13.4 in)
Distance Between Centers	350 / 650 / 1,000 / 1,500
Grinding Wheel Size	510 x 75 mm (20.1 x 3.0 in)
Wheel Speed Max	45 m/s (8,858 sfm)
X-Axis Travel	275 mm (10.83 in)
Z-Axis Travel	525 mm (20.67 in)
Min Feed Increment	0.0001 mm (0.000004 in)
Rapid Traverse X	10 m/min (394 ipm)
Rapid Traverse Z	15 m/min (591 ipm)
Workhead Speed	10 - 400 RPM
Workhead Center	MT5
Swivel Angle	+/- 6°
Machine Weight	6,000 kg (13,228 lb)
Floor Space	3,800 x 2,500 mm (150 x 98 in)
CNC Control	Okuma OSP-P300G
Max Grinding Dia	Ø300
Grinding Wheel Odxid	Ø455x127
Max Grinding Wheel Width	75
Rapid Traverse Rate	16
Wheel Spindle Motor	7.5
Okuma Global Repair Center	Charlotte, North Carolina
Inches	Metric

Specifications sourced from okuma.com — verified 2026-03-28

Strengths & Limitations

Strengths

340 mm maximum grinding diameter handles medium to large diameter components including flanges, gear blanks, and larger bearing races that the GA-W series can't accommodate
510 mm grinding wheel diameter provides more grinding surface area and longer intervals between dressing cycles compared to the 455 mm wheels on the GA-W series
FII generation updates bring improved gap elimination algorithms and faster control processing for reduced cycle times on production work
0.0001 mm infeed resolution maintains the same ultra-fine feed control as the smaller GA models, ensuring precision on larger-diameter workpieces
Hydrodynamic wheel spindle bearings deliver vibration-free grinding for consistent surface finish quality across the larger workpiece range
CBN wheel compatibility enables high-productivity grinding on hardened steel components with extended wheel life

Limitations

500 mm between centers is relatively short for the 340 mm diameter capacity, limiting the machine to compact, large-diameter parts rather than long shafts
10-400 RPM headstock range is slightly lower than the GA-W models' 500 RPM, potentially limiting surface speed on very small diameters
Single wheelhead design requires table swivel for taper grinding; no turret or multi-wheel head options for complex multi-operation grinding
Larger machine footprint than the GA-W series requires more floor space for what may be similar production volumes
OSP-P300G proprietary control limits operator interchangeability with shops running Fanuc or Siemens-controlled grinders

Best For

Automotive manufacturers grinding large-diameter transmission components, differential housings, and bearing journals exceeding 250 mm diameter Aerospace shops grinding turbine disks, spacer rings, and bearing housing ODs that require precision cylindrical grinding on larger-diameter parts Heavy equipment manufacturers grinding large hydraulic cylinder rods, pump shafts, and gear blanks in the 250-340 mm diameter range Bearing manufacturers grinding larger bearing race ODs and roller components that exceed the capacity of the GA-W series General precision manufacturing shops needing a versatile grinder for medium to large diameter components across multiple industries

Frequently Asked Questions

01 What does an Okuma GP-GA-34FII cost?

New pricing ranges from $200,000-$280,000 depending on options. The price is comparable to the GA26W despite the larger diameter capacity because the shorter bed reduces material costs. In-process gauging, CBN wheel compatibility upgrades, and loading automation are common options.

02 What's the difference between the GA-F and GA-W series?

The GA-F series offers larger grinding diameters (340mm+ vs 250mm max on GA-W) and uses larger 510mm grinding wheels. The GA-W series prioritizes longer between-centers distances. Choose GA-F for larger diameter parts and GA-W for longer shaft-type parts. The F series targets flange and disc-type components, while the W series targets shaft-type work.

03 What does the FII designation mean?

FII indicates the second generation of the GA-F series. The updates primarily affect the control system (improved OSP-P300G with faster processing and better gap elimination algorithms) and minor mechanical refinements. The FII models offer better cycle times and improved in-process gauging integration compared to the original F series.

04 Can the GA-34FII grind hardened steel?

Yes, hardened steel grinding (55-65 HRC) is a primary application. Use conventional aluminum oxide wheels for standard production or CBN wheels for higher productivity and better surface finish consistency. The 0.0001 mm feed resolution and hydrodynamic bearings enable precision finishing on hardened surfaces.