Sinker EDM Machine

-- Steady & Reliable Manufacturer --

Brief Product Description

A sinker EDM machine, also known as a ram or cavity EDM machine, burns the shape of a prepared electrode into a hardened workpiece using controlled sparks in dielectric oil. It handles geometry that cutters cannot reach, such as deep narrow ribs, sharp corners, and detailed textures, while leaving the heat-treated hardness of tool steel untouched.

Sinker EDM machines are purchased by mold makers, tool and die shops, aerospace subcontractors, and distributors. Practical buying questions center on electrode wear, the size of the electrode that the head can carry, the flushing method, the jump and orbit functions, and how quickly the generator can rough and then finish within one setup. Reliable servo motion on the Z axis decides whether deep cavities burn cleanly.

Nantong New Era Technology Co., Ltd. brings more than 20 years of numerical control and CNC machine tool experience to each sinker EDM machine we build. We can adapt the controller language, electrical standard, color, and accessories under OEM and ODM terms. Sample burns can be arranged before purchase, and standard models can be ordered in single units. Tell us your material, cavity depth, and surface target, and we will suggest a matching configuration.

When choosing a sinker, think about how your shop prepares electrodes and how often cavities run unattended. A machine with strong jump control, reliable flushing, and protection alarms supports longer unattended burns and lowers labor cost per part. We can also advise on starting parameters for graphite and copper electrodes, which shortens the learning curve for new operators and reduces wasted electrode material in early trials.

Machine ClassRam-type sinker EDM
Electrode ChoiceGraphite, copper, copper tungsten
Key ParametersJump speed, orbit, flushing, finish range
Typical UsersMold, tool and die, aerospace shops
CustomizationController language, color, accessories
Order TermsSample burn, single unit, export packing

Product Overview

A sinker EDM machine produces cavities by lowering a formed electrode toward a conductive workpiece. As the gap closes to a few hundredths of a millimeter, sparks jump across it and erode material. The electrode wears slowly, which is why roughing and finishing are often done with separate electrodes or with orbit steps that enlarge the cavity to size.

What separates a good sinker from an average one is the control of the gap. The servo head must retract in short jumps to clear debris and then return without touching the work. Strong flushing, well-tuned generator pulses, and a rigid column make deep cavities safe to run without constant supervision, and that directly reduces labor cost per part.

HeadServo-driven jump motion
FlushingPressure, suction, or side flushing
WearLow-wear pulses for graphite
SafetyLevel and temperature protection

Main points for buyers

Ask about jump speed and Z-axis response for deep cavity work
Check that the head can carry the heaviest electrode you plan to use
Compare flushing options, including pressure and suction
Look for a generator with both fast roughing and low-wear finishing
Confirm the workpiece fixing method and available accessories

What affects landed cost

When you compare sinker EDM quotations, align the scope first: tank, controller, flushing accessories, and electrode clamping tools should be listed clearly. Then add packing, sea or air freight, insurance, port charges, import duty, and installation labor. Consumables such as filters, oil, and graphite should be included in the annual cost so that the true price of ownership is visible.

Specification

Parameter	Specification
Machine Type	Sinker (ram) EDM
Worktable Size	450 x 280 mm to 1100 x 650 mm
X / Y / Z Travel	300 x 200 x 250 mm to 900 x 550 x 450 mm
Max Workpiece Weight	500 kg to 2200 kg
Max Electrode Weight	50 kg to 220 kg
Max Machining Current	40 A to 80 A
Z-axis Drive	AC servo with jump function
Flushing Methods	Pressure, suction, side flushing
Best Surface Finish	Down to about Ra 0.2 um
Orbit Modes	Circular, square, and custom programmable
Tank Capacity	250 L to 900 L
Protection	Oil level, temperature, and arc protection
Control	CNC controller with process library
Power Supply	380 V, 3 phase, 50 Hz, others on request

Application

Application Scenarios

Industry	Typical Parts	Buyer Focus
Plastic Molds	Cavities with ribs and textures	Fine finish, low wear, repeatable electrodes
Metal Stamping	Punch and die contours	Sharp corners, size control
Aerospace Tooling	Slots, fixtures, nozzle features	Material range, stable deep burns
Electronic Connectors	Micro mold cavities	Small details, fine finishing, clean surface

Target Customers

Mold ShopsNeed predictable burns for cavities and cores
Tool and Die MakersNeed strong roughing with accurate finishing
SubcontractorsNeed a machine that runs mixed jobs reliably
ResellersNeed a standard model with simple documentation

Suitable and Unsuitable Uses

Suitable Uses

Cavities that need low electrode wear
Hardened steel molds finished after heat treatment
Features with deep narrow ribs
Jobs where orbit finishing can replace polishing

Unsuitable Uses

Through-hole cutting that wire EDM does better
Large volume removal on soft metals
Non-conductive materials
Shops without any electrode preparation ability

Selection Guidance

1. Define cavity depthUse the deepest cavity to choose Z travel and the jump capability of the head.
2. Choose the electrodeGraphite suits fast roughing and complex shapes, while copper often gives a finer finish.
3. Select flushingDeep narrow cavities may need suction or pressure flushing to avoid carbon deposit.
4. Review safetyLook for level, temperature, and arc protection for unattended running.

Usage Notes

Check electrode alignment with a dial gauge before starting
Set jump height and timing to match cavity depth
Monitor temperature of the dielectric during long runs
Remove machining residue from the tank regularly
Keep clamps and fixtures clean and conductive
Log working parameters for each electrode and material

Advantages

Fast jump control
The Z axis retracts and returns quickly to clear debris from deep cavities, which shortens burn time and lowers the risk of arcing.
Orbit finishing
Programmable orbit steps allow one electrode to reach final size in stages, saving the cost and lead time of extra electrodes.
Multiple flushing modes
Pressure, suction, and side flushing can be matched to the part, so carbon deposits are controlled and surface quality stays consistent.
Protection systems
Oil level, temperature, and arc detection protect the part and the machine during unattended work, reducing fire and scrap risk.
Straightforward operation
A graphical controller with stored process settings helps new operators start quickly, which reduces training time and trial burns.
Tailored supply
Language, color, voltage, and accessory options can be set per order, so buyers receive a machine that fits their shop without redesign.

Frequently Asked Questions

Q: What does a sinker EDM machine do?
A: It burns a cavity into a conductive workpiece by eroding material with controlled sparks, using an electrode shaped as the inverse of the cavity.

Q: Is a sinker the same as a ram or die sinking EDM machine?
A: In practice, yes. The names describe the same ram-type machine used for cavities and cores.

Q: How do I choose between graphite and copper electrodes?
A: Graphite removes material quickly and is easy to shape, and copper often gives a finer surface. The best choice depends on part and finish.

Q: What affects electrode wear?
A: Pulse settings, polarity, electrode material, and flushing all affect wear. Our team can suggest starting parameters for your material.

Q: Can I run the machine unattended?
A: With proper flushing, level protection, and fire safety measures, many jobs can run with limited supervision, but local safety rules must be followed.

Q: Do you accept OEM or ODM orders?
A: Yes. We can adjust controller language, color, voltage, and accessories under OEM and ODM terms.