Angle Grinder CAT DX31B 12.5 cm 8500 RPM Brushless Motor

The CAT DX31B angle grinder combines a brushless motor with a 12.5 cm grinding disc and a maximum no-load speed of 8500 RPM. Designed for use with an 18 V Lithium‑Ion battery, this cordless grinder offers a balance of performance and portability for grinding, cutting and surface preparation. The unit has a 2.22 cm bore to accept standard accessories and comes in the brand’s characteristic yellow and black finish. With a declared weight of 4.4 kg, the tool is intended for professional and demanding DIY tasks where cordless operation and sustained speed are required.

Advantages

The brushless motor delivers improved efficiency, reduced maintenance and longer runtime compared with brushed alternatives. The 12.5 cm disc size provides a compact working profile suitable for confined spaces while still enabling effective material removal. A maximum idle speed of 8500 RPM ensures consistent cutting and grinding performance across a range of attachments. Cordless operation on an 18 V Lithium‑Ion battery removes the need for a power cable and increases mobility on job sites. The 2.22 cm bore offers compatibility with common discs and accessory systems, simplifying setup and replacement.

Suitable for (tasks / use cases)

• Metal cutting and edge grinding
• Removing rust, paint and weld spatter
• Masonry cutting with appropriate discs
• Sanding and surface preparation on small to medium areas
• On‑site repairs and maintenance where cordless mobility is needed

Key specifications

• Disc diameter: 12.5 cm
• Maximum no-load speed: 8500 RPM
• Motor type: brushless
• Power source: 18 V Lithium‑Ion battery
• Bore size: 2.22 cm
• Weight: 4.4 kg
• Colour: yellow and black

How to use

Fit a compatible 12.5 cm disc onto the 2.22 cm bore and secure it according to the accessory manufacturer’s instructions. Install a charged 18 V Lithium‑Ion battery and verify the grinder’s guard and side handle are correctly positioned. Start the tool and allow it to reach operating speed before engaging the workpiece; maintain steady, controlled movements and avoid applying excessive force. After use, allow the disc to stop completely, remove the battery, and inspect the disc and tool for wear or damage. Follow all safety instructions in the user manual and use appropriate personal protective equipment.

Usage recommendations

Use discs and accessories rated for 8500 RPM or higher and choose material‑specific abrasive types for best results. For prolonged work, keep spare batteries charged and rotate them to maintain consistent performance. Regularly clean vents and inspect the brushless motor housing for debris to preserve cooling and airflow. Always consult safety guidelines for eye, ear and hand protection when operating an angle grinder.