ONA AX250

$110,000 – $175,000 Updated 2026-03-17

Key Specifications

Work Tank Dimensions

680 x 520 x 350 mm (W x D x H)

X/Y/Z Travel

250 x 200 x 250 mm

Max Workpiece Weight

600 kg (1,320 lb)

Dielectric System

Hydrocarbon oil with suction/injection flushing, programmable flow control

Surface Finish Ra

< 0.15 µm (with fine graphite electrodes)

Control System

ONA NCP with fuzzy-logic adaptive generator control

Overview

The ONA AX250 is a CNC sinker EDM machine from the Spanish manufacturer ONA Electroerosion, designed for precision die and mold production, toolmaking, and complex cavity machining. The AX250 combines ONA's proprietary NCP (Numerical Control of the Process) generator technology with a robust mechanical structure to deliver high metal removal rates, excellent surface finish, and reliable process stability for industrial toolroom and production mold shop environments.

ONA's NCP generator system is the technological centerpiece of the AX250, using fuzzy-logic adaptive control to continuously optimize discharge frequency, pulse duration, and gap voltage in real time. This intelligent control approach prevents arc faults and adjusts machining parameters automatically as cavity depth increases and flushing conditions change — maintaining consistent removal rates without manual intervention. The generator supports a wide range of electrode materials including graphite, copper, and copper-tungsten, with pre-optimized technology tables for common material and electrode combinations.

The machine features a mineral-cast base for superior vibration damping and thermal stability, combined with precision linear guideways on all axes. The dielectric system includes programmable suction and injection flushing with flow control to optimize debris evacuation in complex mold geometry applications. An optional Z-axis servo head with automatic electrode changer (ATC) capability supports multi-electrode unattended production cycles, making the AX250 suitable for overnight lights-out operation.

ONA has been manufacturing EDM equipment since 1956 and is recognized as Europe's leading sinker EDM specialist. The AX250 reflects ONA's deep process knowledge and is widely used by mold makers in the automotive, consumer goods, and medical device sectors across Europe and internationally. The machine is supported by ONA's global technical service network and is available with comprehensive training and applications support.

Full Specifications

Parameter	Value
Work Tank Dimensions	680 x 520 x 350 mm (W x D x H)
X/Y/Z Travel	250 x 200 x 250 mm
Max Workpiece Weight	600 kg (1,320 lb)
Dielectric System	Hydrocarbon oil with suction/injection flushing, programmable flow control
Surface Finish Ra	< 0.15 µm (with fine graphite electrodes)
Control System	ONA NCP with fuzzy-logic adaptive generator control
Generator Power	25 A peak discharge current
Machine Weight	approx. 2,100 kg (4,630 lb)

Strengths & Limitations

Strengths

NCP fuzzy-logic adaptive generator maintains stable machining through changing cavity conditions
Mineral-cast base delivers superior vibration damping versus cast iron structures
ONA's 60+ years of EDM specialization reflected in optimized technology tables
Competitive pricing relative to Japanese sinker EDM machines of similar specification

Limitations

Less brand recognition in North American market compared to Sodick, Mitsubishi Electric, and Makino
Service network in North America is thinner than major Japanese EDM brands
250 mm X/Y travel is modest for larger mold cavity applications

Best For

Automotive and consumer goods mold makers requiring reliable precision sinker EDM European toolrooms seeking high-quality EDM from a specialist manufacturer Medical device toolmakers needing fine surface finish in compact cavity geometries

Frequently Asked Questions

01 Who is ONA Electroerosion and where are their machines made?

ONA Electroerosion is a Spanish machine tool manufacturer founded in 1956 and headquartered in Durango, Basque Country, Spain. ONA is Europe's longest-established dedicated EDM manufacturer and produces both sinker and wire EDM machines. Their machines are designed and built in Spain.

02 What is ONA's NCP generator control system?

NCP (Numerical Control of the Process) is ONA's proprietary generator and process control platform. It uses fuzzy-logic algorithms to adaptively control discharge parameters in real time, preventing electrical arcing, optimizing metal removal rate, and adjusting to changing gap conditions automatically throughout the EDM process.

03 Is graphite or copper the preferred electrode material for the ONA AX250?

Both materials work well with the AX250. Graphite (isostatic grade, such as Poco EDM-200 or equivalent) is preferred for most mold and die work due to its machinability and high removal rates at low electrode wear. Copper is preferred for fine finishing applications and when machining carbide workpieces.