Okamoto ACC-1224DX

$45,000 - $75,000 Updated 2026-03-16

Key Specifications

Table Size

24″ x 48″ to 32″ x 120″

Spindle Power

20 hp

table longitudinal travel

720 mm (28.3 in)

table cross travel

350 mm (13.8 in)

vertical travel

460 mm (18.1 in)

max workpiece height

310 mm (12.2 in)

Overview

The Okamoto ACC-1224DX is a fully automatic CNC surface grinder with a 12 x 24 inch (305 x 610 mm) working table, representing one of Okamoto's most popular models in North America for precision flat surface grinding. Okamoto Machine Tool Works of Japan has been manufacturing surface grinders since 1935, and the ACC series reflects nine decades of grinding machine refinement — the DX designation denotes the current-generation control and automation package that distinguishes it from earlier ACC models.

The ACC-1224DX is built on Okamoto's signature box-way guideway system, which the company has maintained as a design choice despite the industry shift toward linear guideways. Okamoto contends — and many experienced grinders agree — that box ways provide superior damping for surface grinding operations, particularly for heavy cuts and the variable table reversals inherent in reciprocating surface grinding. The machine's bed and column are high-grade Meehanite cast iron, providing a rigid and thermally stable foundation.

The machine's CNC automation handles the complete surface grinding cycle: programmable cross-feed increment per table stroke, automatic downfeed per pass, final spark-out passes, and automatic wheel dressing on a programmable schedule. The Okamoto ACC control — based on a Fanuc platform — presents grinding cycles through purpose-designed screens that make programming straightforward for operators familiar with surface grinding practice but not necessarily with general CNC programming. The control stores multiple program memories for rapid changeover between different part types.

Okamoto's strong North American dealer and service network is a significant practical advantage. Parts availability, field service, and application support are well-established across the US and Canada. Pricing for a new ACC-1224DX typically runs $45,000 to $75,000 depending on options, coolant filtration, and magnetic chuck size. The machine competes with the Chevalier FSG series, the Kent USA KGS-1224 AHD, and ELB-Schliff's smaller smartLine variants in the mid-tier automatic surface grinding segment.

Full Specifications

Parameter	Value
Table Size	24″ x 48″ to 32″ x 120″
Table Longitudinal Travel	720 mm (28.3 in)
Table Cross Travel	350 mm (13.8 in)
Vertical Travel	460 mm (18.1 in)
Max Workpiece Height	310 mm (12.2 in)
Max Workpiece Weight	136 kg (300 lb)
Grinding Spindle Power	3.7 kW (5 HP)
Grinding Spindle Speed	2,900 RPM
Max Grinding Wheel Diameter	355 mm (14 in)
Max Grinding Wheel Width	38 mm (1.5 in)
Table Speed	3 – 25,000 mm/min (0.1 – 985 ipm)
Vertical Infeed Resolution	0.001 mm (0.00004 in)
Guideway System	Box-way (longitudinal and cross)
Magnetic Chuck Size	305 x 610 mm (12 x 24 in)
CNC Control	Okamoto ACC CNC (Fanuc-based)
Spindle Nose To Table Max	23.5″ to 27.3″
Spindle Motor Power	20 hp
Machine Weight	16,540 to 35,200 lbs
Floor Space	213″ x 100″ x 86″ to 357″ x 125″ x 94″

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

Strengths & Limitations

Strengths

Okamoto's box-way design provides excellent damping for surface grinding table reversals and variable cuts — many experienced grinders prefer box ways for surface finish quality over linear guideways
Strong North American service and parts network with Okamoto's established dealer presence — service response and parts availability are consistently better than competing brands of equivalent quality
The 12 x 24 inch table covers the most common die and mold workpiece sizes in North American toolmaking — large enough for most job shop and tool room applications
Purpose-designed Okamoto grinding CNC simplifies cycle programming — operators can program the full surface grinding cycle without general CNC expertise

Limitations

Box-way guideways require periodic adjustment and more maintenance attention than linear guideways as they wear — though Okamoto's way geometry is precise and durable, it is a higher-maintenance design
The 3.7 kW spindle motor is appropriate for precision surface grinding but limits aggressive stock removal — shops needing high material removal rates for rough grinding should specify a higher-powered machine
The ACC control interface, while grinding-optimized, is less flexible for unusual or complex grinding cycles compared to a full Siemens or Fanuc open-architecture CNC

Best For

Tool and die shops grinding mold bases, die plates, core and cavity blocks, and flat tooling where the 12 x 24 inch table covers most typical workpiece sizes Production precision manufacturers performing automated CNC surface grinding of hardened steel components, where Okamoto's reliable cycle automation enables consistent unattended operation North American job shops and contract manufacturers that value Okamoto's established service network — knowing a field service technician and parts are readily accessible is a practical priority Shops transitioning from manual surface grinders to CNC automation, where the Okamoto control's grinding-specific interface reduces the learning curve compared to general-purpose CNC systems

Frequently Asked Questions

01 What is the difference between the Okamoto ACC-1224DX and a conventional automatic surface grinder?

Conventional automatic surface grinders have hydraulically or mechanically controlled automatic cycles for table traverse and cross-feed, but limited programmability. The ACC-1224DX's CNC control adds full programmability of all grinding parameters — infeed increments, spark-out passes, dressing frequency and depth, and table speed — stored in named programs. This allows the machine to automatically adapt its cycle for different parts and repeat complex multi-pass grinding programs consistently without operator intervention beyond loading and unloading.

02 Why does Okamoto use box ways instead of linear guideways on the ACC series?

Okamoto's engineering position is that box-way (flat and V-way) guideways provide superior vibration damping for reciprocating surface grinding operations compared to recirculating ball-type linear guideways. The sliding contact of box ways dissipates vibration energy from table reversals and grinding wheel contact more effectively than the point contact of ball-type linear guides. Many precision grinders agree that box-way machines produce slightly better surface finish in direct comparison tests. The tradeoff is higher maintenance — box ways need periodic scraping or replacement as they wear — versus linear guideways that are essentially maintenance-free.

03 What magnetic chuck size and holding power does the ACC-1224DX use?

The ACC-1224DX uses a 305 x 610 mm (12 x 24 in) permanent magnetic or electromagnetic chuck as standard, matched to the table size. Electromagnetic chucks allow holding strength to be varied and can be demagnetized to release parts; permanent magnetic chucks provide constant holding force without power. Holding force is typically rated at 8–12 kg/cm² for electromagnetic types and slightly higher for permanent magnetic. For thin workpieces or materials with low magnetic permeability, shimming, auxiliary fixturing, or surface-area maximization is necessary.

04 How does the ACC-1224DX compare to the ACC-1632DX?

The ACC-1632DX is Okamoto's larger 16 x 32 inch (406 x 813 mm) table model. It accommodates wider and longer workpieces, has a heavier-duty spindle (typically 5.5 kW vs. 3.7 kW), and is rated for higher workpiece weights. The ACC-1224DX is appropriate for most tool room and job shop work; the ACC-1632DX is the choice for shops regularly grinding large mold bases, wide die plates, and fixtures that exceed the 12-inch table width or 24-inch table length.

05 What is the expected flatness accuracy of the ACC-1224DX?

Okamoto specifies the ACC-1224DX for flatness accuracy of 0.003 mm or better over the table length under standard grinding conditions with properly maintained guideways. Parallelism (top surface to bottom surface of the workpiece) is typically held to 0.003–0.005 mm for normal production grinding. For gauge-quality work requiring flatness better than 0.002 mm, a machine with a mineral casting base and premium guideways is typically recommended, though an ACC-1224DX in excellent condition with careful setup can approach these levels.