Xiaomi Mijia Electric Grinding Pen 22000 RPM Cordless Tool – MJDMB001QW Brushless Rotary Tool

Xiaomi Mijia Electric Grinding Pen 22000 RPM Cordless Tool – MJDMB001QW Brushless Rotary Tool

The Xiaomi Mijia Electric Grinding Pen MJDMB001QW is a compact cordless rotary tool designed for precision grinding, polishing, engraving, carving and small drilling applications.

Its high-performance brushless hollow-cup motor provides a variable no-load speed of approximately 15,000–22,000 RPM, giving users control for different materials and tasks. Xiaomi describes the tool for applications including wood carving, sanding, polishing jade and silver, model making and small drilling work.

The slim 2cm pen-style body is made from anodised aluminium alloy and is designed for a comfortable, controlled grip. The tool weighs approximately 310g and comes with a portable storage case containing 16 grinding bits.

The Mijia grinding pen also supports both cordless battery operation and direct plug-in use, making it convenient for short precision jobs as well as longer work sessions.

Common Problems with Traditional DIY Tools

Precision work can become difficult when using bulky power tools.

Common problems include:

• Limited control during detailed work
• Bulky tools that are difficult to grip
• Excessive vibration during polishing
• Limited speed adjustment
• Cables getting in the way
• Separate accessories requiring additional purchases
• Difficulty reaching small or delicate work areas

A compact rotary grinding pen provides a more controlled alternative for small-scale DIY and creative projects.

Smart Solution for Precision DIY Work

The Xiaomi Mijia Electric Grinding Pen combines a slim pen-shaped body, adjustable high-speed rotation and multiple interchangeable bits in one compact tool.

How It Works

Select Bit → Install Accessory → Adjust Speed → Perform Grinding / Polishing / Engraving

The rear speed-adjustment knob allows the user to vary the rotational speed between approximately 15,000 and 22,000 RPM.

Key Features

1. Up to 22,000 RPM Brushless Motor

The Mijia grinding pen uses a durable brushless hollow-cup motor with a maximum no-load speed of approximately 22,000 RPM.

The normal starting no-load speed is around 15,000 RPM, with the speed increasing as the adjustment knob is rotated. Actual operating speed can vary depending on the load and material.

2. Adjustable Speed Control

A dedicated speed-adjustment knob allows users to control the rotational speed according to the task.

Lower settings can be useful when starting delicate work, while higher speeds can provide faster material removal or polishing where appropriate.

3. Cordless & Plug-In Operation

The grinding pen supports two power modes:

• Rechargeable lithium-battery operation
• Direct plug-in operation

This provides greater flexibility when working away from a power outlet or when longer operating time is required.

4. 800mAh Rechargeable Battery

The built-in lithium-ion battery has a rated capacity of 800mAh at 3.7V.

Xiaomi specifies up to approximately 60 minutes of continuous operation on a full charge under controlled test conditions. Actual runtime depends on workload, material and operating conditions.

5. Type-C Charging

The grinding pen uses a USB Type-C charging interface.

Xiaomi specifies charging parameters of 5V⎓1A and a charging time of approximately 90 minutes. For direct plug-in use, Xiaomi recommends a 5V⎓3A power source.

6. Slim 2cm Pen Design

The pen body has a diameter of approximately 20mm, making it easier to hold and control during detailed work.

The aluminium-alloy construction and ergonomic grip are designed for comfortable handling during precision applications.

7. 16 Precision Grinding Bits

The package includes 16 grinding bits with 2.35mm shanks, covering different grinding, polishing, drilling and finishing requirements.

Depending on the accessory, the set includes items such as:

• Wool polishing wheels
• Twist drill bits
• Diamond grinding bits
• Abrasive grinding bits
• Rubber grinding heads
• Wool grinding heads

8. Tool-Free Accessory Installation

The accessory mechanism is designed to allow bits to be installed and removed by twisting the pen head rather than requiring a separate wrench.

9. Portable Storage Case

The grinding pen and accessories come with a compact storage case designed to keep the bits organized.

The case also uses an automatic lifting mechanism that raises the accessory set when opened, making the bits easier to access.

10. Low-Vibration Precision Work

The pen-style design and brushless motor are intended to provide controlled operation for detailed grinding, polishing and creative work.

Actual vibration depends on the selected accessory, material and operating speed.

Benefits

• Up to 22,000 RPM rotation speed
• 15,000–22,000 RPM adjustable speed
• Brushless hollow-cup motor
• 800mAh rechargeable lithium battery
• Up to approximately 60 minutes runtime
• Type-C charging
• Cordless and plug-in operation
• Slim 2cm pen-style design
• Lightweight approximately 310g
• 2.35mm accessory compatibility
• 16 included grinding bits
• Compact storage case
• Suitable for grinding, polishing, engraving and small drilling
• Easy accessory replacement
• Portable for home and workshop use

Perfect For

The Xiaomi Mijia Electric Grinding Pen is suitable for:

• DIY enthusiasts
• Hobbyists
• Wood carving
• Model making
• Jewelry polishing
• Metal finishing
• Small repair projects
• Craft projects
• Engraving
• Pendant drilling
• Jade and silver polishing
• Small-scale workshop tasks

Xiaomi specifically demonstrates the tool for wood carving, wood/metal/model sanding, pendant drilling and polishing jade, silver and small handheld objects.

Why Choose Xiaomi Mijia Electric Grinding Pen?

The main advantage of the Mijia grinding pen is its combination of high speed, compact size and precision control.

Instead of using a large rotary tool for small jobs, the pen-shaped design provides a more controlled grip for detailed work. The adjustable 15,000–22,000 RPM range and 16 included bits make it versatile for different finishing and crafting tasks.

Xiaomi Mijia Grinding Pen vs Traditional Rotary Tool

How to Use Xiaomi Mijia Electric Grinding Pen

Step 1: Choose the Correct Bit

Select the grinding, polishing, sanding or drilling accessory appropriate for your material and task.

Step 2: Install the Accessory

Insert the compatible 2.35mm shank into the collet and secure it properly. Make sure the bit is firmly tightened before switching on the tool.

Step 3: Start at a Controlled Speed

Turn on the grinding pen and begin at an appropriate lower speed when working with a new material or accessory.

Step 4: Increase Speed Gradually

Use the speed-adjustment knob to increase rotation as necessary for the task.

Step 5: Work with Light Pressure

Allow the rotating accessory to perform the work rather than applying excessive force.

Step 6: Turn Off Before Changing Accessories

Always switch off and disconnect the tool before changing bits or performing adjustments.

Use Cases

Wood Carving

Use suitable carving and grinding accessories for detailed woodwork and small decorative projects.

Model Making

The compact pen design is useful for sanding and finishing model materials where precise control is important.

Jewelry & Small Object Polishing

Suitable polishing heads can be used for small items such as jade, silver and other handheld objects.

Pendant Drilling

Small drill accessories can be used for suitable small-scale drilling tasks such as pendant holes.

Metal Finishing

Appropriate grinding and polishing bits can be used for small metal-finishing jobs.

DIY Crafting

The combination of multiple bits and adjustable speed makes the tool useful for creative hobby and craft projects.

Cleaning & Maintenance

To maintain the grinding pen:

• Switch off the tool before cleaning.
• Disconnect it from external power when applicable.
• Remove dust from ventilation openings.
• Clean accessories after use.
• Inspect bits for excessive wear.
• Replace worn grinding bits when necessary.
• Keep the storage case clean and dry.
• Do not immerse the grinding pen in water.
• Store the tool in a dry location.
• Allow the tool to cool after heavy use.

The grinding bits are consumable accessories and naturally wear down with use.

Important Usage Tips

• Always wear appropriate eye protection when grinding, drilling or polishing.
• Work in a well-ventilated area when producing dust or fine particles.
• Secure the workpiece before starting.
• Keep hands away from the rotating accessory.
• Never touch the rotating bit while the tool is operating.
• Use only compatible 2.35mm accessories.
• Make sure each bit is properly secured before operation.
• Disconnect the tool before changing accessories.
• Do not operate near flammable liquids or gases.
• Keep the tool away from children.
• Start at a lower speed when working with unfamiliar materials.
• For valuable or delicate objects, practice on a suitable test piece first.

The manufacturer’s safety guidance specifically recommends keeping the work area clean and well lit, avoiding flammable environments, securing accessories correctly and disconnecting the tool before adjustments or accessory changes.

Product Specifications

Specifications are based primarily on Xiaomi’s official product and specification pages. Actual runtime and operating speed can vary according to load, accessory and working conditions.

What’s in the Box?

The standard package includes:

• 1 × Xiaomi Mijia Electric Grinding Pen
• 1 × Storage Case
• 16 × Grinding Bits
• 1 × USB Type-C Charging Cable
• 1 × User Manual

These package contents are listed by Xiaomi’s official specification page.

Who Should Buy This Product?

Choose the Xiaomi Mijia Electric Grinding Pen if you want:

• A compact precision rotary tool
• Up to 22,000 RPM performance
• Cordless operation
• Type-C charging
• Adjustable speed control
• A lightweight pen-style body
• Multiple grinding and polishing accessories
• A portable DIY tool
• A tool for crafts, models and small repair work

If you need a heavy-duty tool for large-scale cutting, grinding or industrial applications, a larger professional rotary tool may be more appropriate.

Why Buy from AIYOZON?

When purchasing the Xiaomi Mijia Electric Grinding Pen from AIYOZON, you can enjoy:

• Convenient online ordering
• Detailed product information
• Carefully selected Xiaomi products
• Secure packaging
• Delivery support
• Product assistance
• Customer support for product-related questions

Frequently Asked Questions

What is the maximum speed of the Xiaomi Mijia Electric Grinding Pen?

The maximum no-load speed is approximately 22,000 RPM, with an adjustable range of around 15,000–22,000 RPM.

What is the model number?

The model is MJDMB001QW.

Is the Xiaomi Mijia Grinding Pen cordless?

Yes. It has an 800mAh rechargeable lithium battery for cordless use and also supports direct plug-in operation.

How long does the battery last?

Xiaomi specifies up to approximately 60 minutes of continuous operation on a full charge under controlled conditions. Actual runtime varies with workload and operating conditions.

How long does it take to charge?

The specified charging time is approximately 90 minutes using the listed charging parameters.

Does it use USB Type-C?

Yes. The grinding pen has a Type-C charging port.

What size bits does it use?

It uses accessories with a 2.35mm shank/collet size.

How many bits are included?

The standard package includes 16 grinding bits.

What can I use it for?

It can be used for suitable small-scale engraving, carving, grinding, sanding, polishing and drilling tasks.

Is it suitable for beginners?

Yes. Xiaomi describes the controls as simple, with a power button and speed-adjustment knob. However, beginners should practice on scrap material and use appropriate protective equipment.

Can I use it while charging?

The product supports direct plug-in operation. However, Xiaomi notes that when the device is being used while plugged in, the battery itself does not charge simultaneously; charging begins after use stops.

Is this a heavy-duty industrial grinder?

No. It is better suited to precision DIY, crafting, polishing, engraving and small repair applications rather than heavy industrial grinding.

Final Verdict

The Xiaomi Mijia Electric Grinding Pen 22000 RPM (MJDMB001QW) is a compact and versatile precision rotary tool for DIY enthusiasts, hobbyists and makers.

With its 15,000–22,000 RPM adjustable brushless motor, 800mAh rechargeable battery, Type-C charging, 2.35mm accessory compatibility and 16 included bits, it offers a convenient combination of portability and precision.

Its slim pen-style body and cordless operation make it particularly useful for detailed jobs such as wood carving, model finishing, polishing, engraving and small drilling.

🛠️ Ready for More Precise DIY Work?

• ✔ Up to 22,000 RPM
• ✔ Brushless Motor
• ✔ 15,000–22,000 RPM Adjustable Speed
• ✔ 800mAh Rechargeable Battery
• ✔ USB Type-C Charging
• ✔ Up to 60-Minute Runtime
• ✔ 2.35mm Universal Collet
• ✔ 16 Grinding Bits Included
• ✔ Slim 2cm Pen Design
• ✔ Cordless & Plug-In Operation

👉 Order the Xiaomi Mijia Electric Grinding Pen from AIYOZON today and take your DIY, polishing, engraving and precision crafting projects to the next level.