ER25 4KW Square Air Cooled
220V/380V
10000-18000 RPM
10.5KG
Air Cooled
ER25
4KW
10A
325X134X109mm
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The Zhong Hua Jiang ER25 4kW square air-cooled CNC spindle motor is offered for industrial CNC router integration, spindle replacement, OEM equipment assembly and distributor purchasing. The motor combines ER25 collet tooling, a square mounting housing and high-frequency speed control using a separate, compatible VFD.
Request an ER25 4kW Spindle Motor Quote


The Zhong Hua Jiang ER25 4kW square air-cooled CNC spindle motor is intended for CNC machine builders, spindle distributors, woodworking equipment suppliers, professional engraving shops and industrial replacement projects. The square housing and ER25 collet interface provide a motor-only option for suitable CNC router installations.
The published product configurations include 220V / 380V motor options, 300Hz operation, a speed range of 10,000–18,000 RPM and an ER25 collet interface. The motor requires a correctly matched external VFD. Its cooling fan eliminates the need for a water pump and circulating coolant system.
Discuss an ER25 4kW Spindle Application
View Zhong Hua Jiang Catalogue 2025 (PDF)
Motor details should be checked against the actual variant ordered. The product attributes specify 325 × 134 × 109mm dimensions and 10.5kg motor weight. Confirm the actual motor nameplate and mechanical drawing before order acceptance.
| Specification | ER25 4kW Square Motor |
|---|---|
| Product | ER25 4kW square air-cooled CNC spindle motor |
| Product type | Standalone spindle motor; matching VFD is a separate selection |
| Rated power | 4kW |
| Housing | Square motor body, air-cooled |
| Collet interface | ER25 |
| Motor voltage variants | 220V / 380V (specify the required version) |
| Published speed range | 10,000–18,000 RPM |
| Frequency | 300Hz, as listed in the source specifications |
| Published current | 10A; check the selected motor nameplate |
| Motor dimensions | 325 × 134 × 109mm (published product attributes) |
| Motor weight | 10.5kg (published product attributes) |
| External VFD | Required; frequency, voltage, output current and power to match the selected motor |
| Typical machinery | CNC router, woodworking router, engraving and suitable cutting or milling machinery |
Request ER25 4kW Motor Dimensions and Pricing

| Voltage | 220V / 380V | 1 pcs 4KW square spindle motor |
| Speed | 10000-18000 RPM | 1 pcs pre-soldered aviation wire and 3 pcs wrenches for quick installation |
| Power | 4KW | This spindle should be equipped with a 300Hz VFD |
| Electric Current | 10A | Confirm the actual nameplate rating and VFD output current. |
| Frequency | 300Hz | Do not use settings from a 400Hz variant without confirming compatibility. |
| Weight | 10.5kg (product attributes; verify nameplate) | Published page attributes list 10.5kg; check the variant supplied. |
| Collet | ER25 | Select an appropriate ER25 collet for the cutter shank. |
| Cooling | Air Cooled | Leave motor ventilation paths unobstructed. |
| Usage | CNC engraving machines | CNC router, engraving, woodworking and suitable milling equipment. |
Note: the motor-only package entries shown in the third column are distinct from the motor electrical specifications. The VFD is selected separately.

Typical machining materials include wood, MDF, acrylic, PVC, plastics and light non-ferrous metals. The examples below illustrate possible applications; tool selection, cutting parameters and machine rigidity must be evaluated for the individual project.
Use appropriate routing tools and speeds for wooden signs, MDF furniture panels, plywood and suitable hardwood engraving.
Acrylic and PVC machining benefit from matched cutter geometry, consistent feed and efficient chip evacuation.
Aluminium and brass may require conservative loads, rigid workholding, suitable tools and careful heat and chip management.
Designed for CNC router integration and spindle replacement, this 4kW square air-cooled motor combines ER25 tool holding, high-frequency VFD control and an air-cooling structure. It is suitable for a range of routing and engraving applications when the machine structure, tooling and operating parameters are appropriate.
The ER25 collet interface provides clamping for compatible cutter shank diameters. Select the correct ER25 collet and observe the cutting tool manufacturer’s permitted speeds, clamping requirements and allowable tool overhang.
The published speed range is 10,000–18,000 RPM with 300Hz operation specified in the source table. Use a compatible external inverter and program its motor voltage, frequency, acceleration, current protection and speed limits from the actual spindle nameplate and drive documentation.
The air-cooled motor dissipates heat through its integrated airflow system and does not need an external water pump, tank or coolant piping. Keep air inlet and outlet paths unobstructed and account for workshop conditions when selecting an installation position.
The product attributes list 220V/380V versions and 10A current. Choose a VFD with motor-compatible voltage and output current; do not assume a 220V motor and 380V motor use interchangeable inverter settings. The actual purchased motor nameplate takes precedence.
Confirm 220V/380V Motor and VFD Match

The illustration above refers to different spindle operating versions. This ER25 4kW listing specifies 300Hz and 10,000–18,000 RPM ; do not assume a 400Hz or 24,000 RPM rating for the selected motor.
The manufacturer presents dynamic balancing as a feature intended to limit vibration during spindle rotation. Final vibration and finish depend on correct cutter balance, tool assembly, mounting rigidity, bearing condition and cutting forces.

Buyers seeking a particular bearing material or service specification should request an approved data sheet for the exact model.
The manufacturer describes a four-bearing spindle construction and copper rotor winding. Buyers requiring ceramic or steel bearing construction should confirm the exact bearing specification with the supplier in writing for the ordered variant. Actual service life depends on operating loads, temperature, cleanliness and maintenance.
| Our Spindle Motor | Other Spindle Motor |
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| Runout of less than 0.005mm | Runout of 0.05mm |
The comparison values shown above depend on measurement location, test tooling and instrument. Confirm the agreed runout tolerance and inspection method for precision-critical orders.
The retained images and comparison table illustrate spindle runout values, including less than 0.005mm for the featured motor. Runout should be assessed with a defined collet, measurement point and test method. Agree an inspection criterion for applications requiring controlled concentricity; the illustration alone is not a per-unit tolerance certificate.
Spindle Runout Comparison — Inspection Method Required

The square motor housing provides a different mounting interface from Ø100mm or other round spindle designs. Confirm 325 × 134 × 109mm overall motor dimensions, mounting-hole locations, tool clearance and airflow paths before CNC machine assembly. A pre-soldered aviation cable and three wrenches are listed in the source package information.
Request a Square Spindle Mounting Drawing
This is a motor-only listing , rather than a preassembled motor-and-inverter kit. The published package list names the motor, a pre-soldered aviation wire and three wrenches. Check exact packing details with your quotation.
| 1x | 1 pcs 4KW square air cooled spindle motor |
| 1x | 1 pcs pre-soldered aviation wire and 3 pcs wrenches for quick installation |
| Note | This air cooled spindle motor should be equipped with a 300Hz VFD |
Not included by default: VFD inverter, VFD programming service and additional cutting accessories, unless itemized in the confirmed quotation.
For professional users, distributors and OEM CNC machine builders, quote requests should identify the required motor voltage, mounting details, current VFD or intended inverter, machining materials, order quantity and delivery destination. Additional compatible accessories or bundled motor-and-VFD configurations can be discussed separately.
Request Motor-Only Wholesale Pricing
Explore other air-cooled spindle motors for smaller ER11/ER20 toolholding requirements or higher-power ER32 applications. The linked items below are separate products ; specifications and package contents vary by model.
Compare Related CNC Spindle Motors
Round Air Cooled Spindle Motor Kits
Square Air Cooled Spindle Motor Kits


Huajiang was founded in 2000, starting with the production of CNC engraving spindle motors, then expanding to VFD variable frequency drives and engraving machines.
To explore and develop more international markets, the Zhong Hua Jiang brand was established in 2018.
We have registered patents for our air cooled spindle motor series. Patent No.: 200730184245.5.
We have more than 20 years of manufacturing experience and export CNC spindle motors to global markets, including customers in the USA and Germany.

Zhong Hua Jiang describes manufacturing experience beginning in 2000 and supplies CNC spindles, related drives and other CNC machine components. For procurement, request the applicable motor drawing and specifications for the selected model.
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Quality AssuranceSuperior quality performance Strict quality control | Patents and CertificationsSeveral patents for air-cooled spindle motors | Additional Brand ValueBrand value highly recognized by the market |
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Reasonable PriceDirect factory sales High cost performance | Full Time ServiceProfessional technical support Quick customer service | Fast and Reliable DeliveryFast and efficient delivery Real-time tracking and updates |
Zhong Hua Jiang also supplies CNC router machines, including the 3018, 3020, 3040 and 6090 series, for routing, engraving and small-production uses.
The spindle motor range includes square and round air-cooled motors, water-cooled motors and separately listed motor-and-VFD kits for different machine architectures.
Related CNC equipment includes collets, limit switches, Z probes, emergency-stop devices, electrical cabling and stepper motors for CNC assembly and maintenance.
Contact Zhong Hua Jiang for OEM Supply


This page describes the standalone spindle motor . A matching VFD must be selected separately unless specifically included in a confirmed order. Ask for a separate motor-and-VFD kit quotation if required.
The published motor power is 4kW , and the tool-holding interface is ER25 . Choose an ER25 collet that fits the actual cutter shank.
The product attributes list 220V and 380V versions. Specify the required motor voltage when requesting a quotation. It must match the selected inverter’s output voltage and the machine electrical design.
The published specification lists 10,000–18,000 RPM . The motor nameplate and confirmed variant determine the allowable maximum speed; do not use settings from a different 24,000 RPM spindle.
The supplied specification table references 300Hz . Confirm the actual frequency, voltage and current on the ordered motor before configuring the inverter.
The product attributes specify 325 × 134 × 109mm . Obtain the dimensional drawing for mounting-hole spacing, connector orientation and airflow clearance before finalizing machine design.
The published product attributes list 10.5kg . Confirm the actual motor mass and shipping weight for your selected version and logistics planning.
No standard round clamp should be assumed for this square-housing model. Verify the body mounting points and supporting machine bracket dimensions instead.
ER25 is a collet series with a range of available bore sizes. The actual cutting tool shank must match the selected collet, and the cutter must be rated for the intended speed and cutting load.
Wood routing, MDF processing and engraving are typical applications. Choose appropriate carbide cutting tools, cutter speeds, feeds and chip extraction for the workpiece and machine.
Yes, those materials are among the published applications. Machining quality depends on cutter design, speed, feed, chip removal and avoiding excessive heat buildup.
Light aluminium or brass machining may be possible on a sufficiently rigid CNC machine with suitable tooling, workholding and feed settings. Verify cutting loads and thermal conditions for the application.
Air cooling removes the need for a pump, tank and coolant circulation tubing. It requires unobstructed airflow. A water-cooled spindle uses a separate coolant loop and may have different noise and duty-cycle characteristics.
The stated package includes one ER25 4kW square spindle motor, one pre-soldered aviation wire and three wrenches . Confirm the packing list in the purchase order; VFD and additional cutting accessories are not listed as standard contents.
Do not assume compatibility based only on an inverter’s model name. The selected VFD must satisfy the motor’s voltage, frequency, output-current and power requirements. Ask the supplier to review the actual ratings before purchase.
This product series is described with a four-bearing construction. Please confirm whether the exact model supplied uses ceramic or steel bearing components before finalizing a purchase that requires a specific bearing material.
The runout comparison graphic states a value below 0.005mm, but measurement conditions are not specified. For critical tolerances, agree the test position, collet, instrument and acceptance criteria with the supplier.
It may be a suitable replacement if the machine can accommodate its housing and weight, required supply, matching VFD, tool clearance and ventilation. Compare the original spindle drawing and electrical data before ordering.
The motor is controlled through a compatible VFD. Controller-to-VFD integration, including start/stop and speed commands, depends on the particular drive and machine controller interfaces.
The listed product uses ER25 collet tooling; an automatic tool-changing mechanism is not specified. For automatic tool changing, inquire about a dedicated ATC spindle.
Zhong Hua Jiang offers spindle products for dealers, wholesalers and CNC machine builders. Include your expected order volume, motor configuration, destination market and purchase schedule when requesting pricing.
OEM branding, labeling, packaging, wiring and accessory requirements can be discussed. The available configuration, order quantities and quotation terms are subject to confirmation for the specific project.
Minimum order quantity, production schedule and warranty coverage should be confirmed in the current written quotation and purchase agreement for the selected motor.
Provide the requested 220V or 380V version, required ER25 tooling, machine application, mounting drawings, VFD specifications, quantity, destination country and any testing or packing requirements.
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