There is a common misconception when handling lubricants on the mold machining shop floor: the belief that “oil must always be thick and highly viscous to protect molds effectively.” For processes using general stamping or press oils, this might be true to some extent, as a strong oil film prevents physical friction.

However, in Electrical Discharge Machining (EDM)—a process that precisely shapes metal using electricity—this conventional wisdom is completely turned on its head. To get straight to the point, if the viscosity of EDM fluid is unnecessarily high, it actually drags down machining speeds and becomes the primary culprit behind critical quality defects. Let’s fact-check exactly why this happens.

1. EDM is not ‘physical friction,’ but an ‘electrical explosion.’

Unlike conventional metal machining, the copper or graphite electrode in EDM does not directly touch the workpiece. The process works by maintaining a microscopic gap and generating tens of thousands of electrical sparks (arcs) to instantly melt and erode the metal surface.

Therefore, the role of EDM fluid is not ‘lubrication’ to prevent physical collision between metals, but rather the following three functions:

• Insulation: Acting as a dielectric barrier to ensure sparks fire precisely at the desired moment.
• Cooling: Dissipating the intense heat from the sparks, which can reach thousands of degrees.
• Flushing: Washing away the melted metal debris (chips).
• Here, viscosity is the key factor that directly impacts this third function: ‘flushing.’

2. The Fatal Flaw of High Viscosity: ‘Degraded Flushing Efficiency’

During electrical discharge machining, an immense volume of metal particles and carbon sludge accumulates within a narrow clearance of under 0.01mm. What exactly occurs if these byproducts stagnate in the machining zone?

• Occurrence of Secondary Discharges: Sparks that are supposed to strike the surface of the workpiece hit the floating debris instead, detonating in the wrong places. This ruins the surface finish—which should be as smooth as a mirror—and causes irregular wear on expensive electrodes.

• Drastic Drop in Machining Speed: When the discharge gap becomes unstable because debris cannot escape, the EDM machine’s sensors halt spark generation and repeatedly lift the electrode (a motion known as ‘jumping’ or retraction). The stickier the oil, the slower it washes away this debris, leading to an exponential increase in total cycle time.

3. How Low-Viscosity EDM Fluid Boosts Machining Speed

Using an optimized, low-viscosity EDM fluid resolves all of these issues.

• Exceptional Penetration and Flushing Power: Low-viscosity fluid, flowing as freely as water, rapidly penetrates to the very bottom even during narrow and deep-hole machining to instantly flush out microscopic chips.

• Stable Discharge Maintenance: Because the rapid evacuation of chips keeps the spark gap perfectly clean, the machine can continuously fire sparks at 100% speed without any unnecessary interruptions.

• Superior Cooling Efficiency: Lower viscosity facilitates better heat conduction and fluid convection. This rapidly dissipates heat from the machining zone and prevents the thermal deformation of the mold.

4. Dyna Solution’s Technological Prowess: The Perfect Balance Between ‘Low Viscosity’ and a ‘High Flash Point’

Does that mean an oil as thin as water is always the absolute best? Unfortunately, from a fluid dynamics perspective, lowering an oil’s viscosity simultaneously lowers its flash point. This creates a paradox where the risk of fire increases dramatically.

Dyna Solution Co., Ltd. has completely overcome this paradox through special additive blending and synthesis technologies accumulated over the past 30 years.

Dyna Solution’s EDM fluid is a high-end product that maintains an ‘ultra-low viscosity’ optimized for chip evacuation while simultaneously achieving a ‘high flash point’ that thoroughly eliminates fire hazards. On top of this, our powerful ‘sedimentation’ technology quickly settles debris to the bottom of the tank, drastically extending your filter’s lifespan.

Based on this proven excellence, our fluids have passed rigorous performance tests and are currently being supplied to major corporations in Korea.

Are you struggling with machining speeds that just aren’t what they used to be, no matter how much you tweak the EDM settings? Are you dealing with surface pitting defects or frequent filter clogging? There is a high probability that it is not a machine issue, but rather an ‘oil viscosity’ problem. Experience Dyna Solution’s customized EDM fluid solutions today and achieve the ultimate combination of workplace safety and maximum production speed.

Dyna Solution Co., Ltd.
Industrial Lubricant Solution
E-Mail : dyna@dynachem.co.kr
Web : dyna.co.kr/en/