The FUJI HGC-902 250Hz high-frequency grinder and motor-generator frequency converter form a complete grinding system for foundries and shipyards introducing high-frequency equipment for the first time. The approximately 4.7kg, 180mm (7-inch) angle grinder is intended for medium-duty casting fettling, flash removal and surface treatment, paired with an application-matched FUJI grinding wheel.
250Hz is an established operating frequency for high-frequency power tools in Japan. FUJI's 250Hz tool technology has 30 years of use in the Japanese market. The HGC-902 runs on a compatible 250Hz, three-phase 200V supply, using a three-phase squirrel-cage induction motor without carbon brushes or a commutator.
This is an AC induction motor, not a brushless DC motor. The system requires a suitable high-frequency power source; it must not be connected directly to an ordinary 50/60Hz outlet. Learn more about FUJI high-frequency grinding technology.
The 7-inch HGC-902 weighs approximately 4.7kg. Compared with larger European 230mm (9-inch) 300Hz grinders, this 180mm configuration prioritizes manageable handling for medium-duty work. For operators who find larger tools tiring to lift, position and guide, the smaller FUJI configuration offers a more manageable option while retaining useful capacity for foundry grinding.
This comparison concerns different tool sizes and models. Lower frequency alone does not make a grinder lighter or more durable. A 9-inch tool may be appropriate for a different removal task; selection should consider casting size, access, wheel capacity and operator handling. Assess the working weight with the wheel and accessories fitted, and include cable handling in a trial.
Foundry production requires a grinding setup matched to the casting and the operator's task.
| Angle grinder | FUJI HGC-902, 7-inch high-frequency angle grinder |
|---|---|
| Power supply | 250Hz, three-phase 200V; compatible high-frequency supply required |
| Motor | Three-phase squirrel-cage induction motor; no carbon brushes or commutator |
| Tool weight | Approximately 4.7kg; confirm the exact supplied configuration when ordering |
| Grinding wheel | 180mm FUJI zirconia wheel for casting grinding, or an application-matched modified Super F2 aluminium oxide depressed-centre wheel |
| Workpiece and tasks | Gray cast iron automotive components; flash removal and casting surface cleanup |
Confirm the wheel thickness, bore, mounting arrangement and marked maximum operating speed against the HGC-902 specification. A 180mm diameter alone does not establish compatibility. Use a grinding wheel for its intended grinding operation, not as a substitute for a cutting disc.
FUJI high-frequency system illustration. Confirm the supplied grinder and power-source specifications for the HGC-902 configuration.
For gray cast iron, FUJI recommends evaluating a dedicated zirconia casting-grinding wheel when removal rate is the main priority, or a modified Super F2 aluminium oxide depressed-centre grinding wheel for an economical medium-duty option. The modified wheel should be specified for the actual casting and high-frequency grinder; do not assume that every standard Super F2 variant is identical to the proposed foundry specification.
Compare both options on the same casting feature. Record time to the required profile, wheel wear and any additional finishing. A wheel that removes more material per minute is useful only if the casting remains within its dimensional and surface requirements. For background on the family, see FUJI Super F2 grinding wheels; confirm the application-specific version with FUJI.
| Workstation | Why evaluate this package | Selection limit |
|---|---|---|
| Small and medium gray iron castings | Repeated flash removal, parting-line cleanup and accessible surface irregularities. | Preserve the casting profile; confirm access and removal allowance. |
| Automotive casting finishing | A manageable tool for repeated handling around component features. | Judge accepted parts per shift, not free-running speed alone. |
| Shipyard steel fabrication | Medium-duty weld cleanup and local surface treatment with a wheel approved for the steel. | A wheel selected for cast iron is not automatically the right specification for steel or propeller alloys. |
| Large gates, risers and sustained heavy stock removal | Assess whether a larger, higher-output tool or another approved process is needed. | Do not present a 180mm grinder as equivalent to a 230mm heavy-removal machine. |
The approximately 4.7kg tool can reduce the weight that operators must lift and reposition compared with a larger machine. It does not guarantee fatigue-free operation. Wheel weight, accessories, cable drag, posture and work/rest arrangements all affect handling over a shift.
On gray iron automotive castings, the objective is to remove unwanted material while preserving the required component profile. The compact 7-inch format is useful where repeated repositioning and access around casting features matter as much as the maximum removal capacity of a larger wheel.
The selected abrasive wheel and high-frequency tool should be evaluated as a working combination. Actual output depends on casting geometry, material condition, wheel grade, operator technique and the required finish. Explore related foundry grinding applications.
The power source in this package is a motor-generator frequency converter, also called a rotary frequency converter. It converts the factory supply into the high-frequency electrical supply required by the grinder. It is a separate part of the installation, not an ordinary mains outlet or a fuel-powered portable generator.
FUJI can configure the package for three-phase 200V or 380V, 50Hz or 60Hz factory input, subject to selecting the correct converter version. These are input-side options, not a statement that every converter accepts all voltages and frequencies. The HGC-902 tool supply described here is three-phase 200V at 250Hz. Have the input and output nameplates, protection and installation requirements checked before connection.
Size the converter for the planned number of grinders operating at the same time, including starting and working loads. Cable length, voltage drop, connectors, earthing, ventilation and the converter’s location must be included in the system review. Do not infer the number of supported tools merely from the number of sockets.
For an HGC-902 installation, confirm 250Hz and three-phase 200V at the tool supply, together with available capacity, connectors, cables, earthing and protection. FUJI can help select a compatible grinder and power-source package after reviewing the site supply and number of tools to be operated.
If your plant already uses 300Hz infrastructure, consider the HGC-3902 300Hz model as a separate selection route. Matching frequency is only one requirement: confirm voltage, connections, capacity and manufacturer-approved compatibility before connecting any tool. The 250Hz HGC-902 should not be treated as a direct substitute on a 300Hz supply.
See the 7-inch high-frequency grinder range for related configurations.
For a workshop with no existing high-frequency infrastructure, the FUJI 250Hz grinder-and-converter package offers a coordinated starting point. FUJI reports 30 years of Japanese-market experience with this technology. This is experience with the system family, not a 30-year service-life guarantee for each individual tool.
If the plant already has European 300Hz equipment, assess a compatible 300Hz tool instead of connecting a 250Hz grinder to that supply. Both systems can support industrial work when correctly matched. Frequency alone does not determine torque, weight or productivity, and not every European 300Hz tool is a 9-inch model. See the separate 300Hz foundry replacement planning case for that installation route.
A useful foundry trial compares the same casting, removal task and acceptance criteria. Record:
When comparing with air tools, account for the compressed-air system rather than comparing only motor ratings. These measurements provide a basis for estimating cost per finished casting; no fixed productivity or energy-saving percentage applies to every installation.
Application illustration. Assess tool access, posture and handling on the actual workpiece during a trial.
The induction motor eliminates carbon-brush replacement, but the grinder still requires inspection and maintenance. Follow the tool manual for checks of gears, bearings, cables, connectors, guards and mounting parts. Damaged or worn components should be assessed and replaced as required; stop using a tool with abnormal vibration, noise or damaged electrical parts.
Use appropriate PPE, secure the casting and follow the wheel and tool instructions. Lower tool weight does not remove vibration exposure or other grinding risks. Plan working methods and exposure controls using the relevant grinder vibration and HAVS guidance.
Yes. Contact FUJI with the casting material, photographs, grinding task, existing equipment and available power supply. Our team can discuss a suitable trial arrangement, including regional availability and the proposed wheel configuration.
The grinder requires a compatible 250Hz, three-phase 200V tool supply. For a new installation, FUJI selects a motor-generator converter to suit the factory input: three-phase 200V or 380V at 50Hz or 60Hz, according to the converter version. Send the factory and converter nameplates for review; do not connect the grinder directly to ordinary mains or a 300Hz supply.
The HGC-902's smaller format and weight of approximately 4.7kg can make repeated positioning more manageable. A larger tool may suit a different removal requirement. Compare access, cycle time and operator handling on your casting rather than choosing by frequency alone.
No. It uses a three-phase squirrel-cage induction motor without carbon brushes or a commutator. Gears, bearings and other mechanical or electrical components still require maintenance.
Request the current documentation and warranty terms for the exact model and destination market before ordering. Service life depends on use and maintenance; it is separate from the agreed warranty. FUJI can also discuss replacement parts and service support.
FUJI combines grinding-wheel expertise with high-frequency tool application support. 30 years of Japanese-market use underpin its 250Hz technology. For foundries, the practical focus is a suitable tool, abrasive and power supply working together on the required casting cleanup task.
Share the workpiece material and photographs, grinding task, current equipment, three-phase factory voltage and frequency, intended number of simultaneous operators, and cable distances. FUJI can propose the grinder, motor-generator converter and wheel combination and discuss a trial on your parts.
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