Makita GA9020 Angle Grinder
The Makita GA9020 is a corded angle grinder designed for heavy-duty cutting, grinding, and surface preparation applications in construction, metal fabrication, and stone work. The model designation "GA9020" identifies it within Makita's angle grinder product line, with this model representing the successor to the earlier 9067/9069 series and featuring durability higher than its predecessors.
The angle grinder is characterized by its powerful 2,000-watt motor delivering consistent power for demanding applications across construction sites, fabrication shops, and maintenance operations. The motor drives the 230mm (9-inch) wheel at 6,600 revolutions per minute no-load speed, providing the peripheral speed necessary for efficient material removal in both metal and masonry applications.
The GA9020 accommodates maximum wheel diameter of 230mm with 22mm bore and M14 x 2mm spindle size, accepting standard grinding wheels, cutting discs, and diamond blades commonly used in professional applications. The grinder weighs 5.8 kilograms, providing sufficient mass for stable operation while remaining manageable for extended use periods. The tool is available in both 110V and 240V versions to suit different electrical infrastructure requirements.
Technical Specifications
Motor and Power System
The GA9020 operates from a 2,000-watt fan-cooled motor powered by mains electricity, providing consistent power independent of battery charge states. The motor's substantial power output enables the grinder to maintain cutting speed under load when working through thick metal sections, dense masonry, or other materials that would bog down less powerful tools. The fan cooling system dissipates heat generated during sustained operation, preventing thermal overload and maintaining performance during extended cutting or grinding sessions.
Rotational Speed
The grinder delivers 6,600 RPM no-load speed, which translates to approximately 80 metres per second peripheral speed with 230mm wheels. This speed provides the cutting velocity necessary for efficient material removal across diverse applications from steel cutting to concrete grinding. The single-speed design eliminates speed selection complexity, with the 6,600 RPM speed representing a compromise optimized for the 230mm wheel diameter.
Wheel Specifications
The GA9020 accommodates maximum wheel diameter of 230mm (9 inches) with maximum wheel thickness of 6.5mm, accepting the full range of 230mm grinding wheels, cutting discs, and diamond blades available from abrasive manufacturers. The 22mm bore diameter represents the standard European bore size, ensuring compatibility with wheels from multiple manufacturers. The M14 x 2mm spindle provides robust wheel mounting capable of withstanding the high lateral forces generated during heavy grinding and cutting operations.
Physical Specifications
The angle grinder weighs 5.8 kilograms, providing good balance between sufficient mass for stable cutting and grinding, and manageable weight for extended operation. This weight proves lighter than petrol-powered cut-off saws commonly used for similar applications, while avoiding the starting difficulties and maintenance requirements of petrol equipment. The grinder features a soft grip rear handle for user comfort and improved grip during operation.
Noise and Vibration
The GA9020 generates sound pressure of 89 dB(A) and sound power of 100 dB(A) with uncertainty factor of 3 dB(A), requiring hearing protection during operation. Vibration with artificial wheels measures 5.5 metres per second squared, with uncertainty factor of 1.5 m/s². Users should monitor exposure duration to maintain compliance with hand-arm vibration exposure limits, particularly during extended cutting or grinding sessions.
Key Features
Labyrinth Construction Anti-Dust System
The GA9020 incorporates labyrinth construction that seals the motor from dust and debris by creating a complex set of channels that prohibit contamination entry. This superior anti-dust structure protects the armature, extending motor life significantly when operating in the dusty environments typical of construction sites and fabrication shops. The protective zig-zag varnish further seals motor and bearings from dust ingress, maintaining performance reliability over extended service life.
Machined Bevel Gears
The grinder employs machined bevel gears throughout its drive train, providing superior strength and durability compared to cast gears. Machined gears deliver smoother rotations and more efficient transfer of energy from motor to spindle, reducing power losses and maintaining cutting performance. The precision machining ensures accurate gear meshing that minimizes vibration and noise while maximizing power transmission efficiency.
Rotatable Gear Housing
The gear housing can be positioned at every 90 degrees, enabling users to orient the side handle and wheel guard to optimal positions for different cutting and grinding operations. This adjustability accommodates working in confined spaces, cutting at various angles, and grinding surfaces with different orientations without requiring awkward tool positioning. The tool-less adjustment mechanism facilitates rapid reconfiguration between applications.
Two-Stage Safety Switch
The GA9020 features a 2-stage on/off switch requiring users to push the switch forward then pull up, preventing accidental activation. This dual-action requirement ensures the tool cannot be inadvertently started during transport or when setting the grinder down, reducing the risk of accidents from unintended operation. The large trigger switch design accommodates gloved operation while maintaining positive control.
Three-Position Side Handle
The grinder includes a three-position side handle that can be mounted in multiple locations around the gear housing to suit operator preference and application requirements. The repositionable handle enables comfortable two-handed operation regardless of cutting angle or work position, improving control and reducing operator fatigue. The handle design incorporates soft-grip materials for enhanced comfort during extended use.
Applications
Construction Site Cutting
The GA9020 has been adopted by the construction industry for cutting applications across diverse materials. When fitted with a diamond blade, the GA9020 will cut anything from roof tiles to paving slabs, providing a lighter and more convenient alternative to petrol cut-off saws. The 2,000-watt motor delivers sufficient power for cutting through thick concrete, reinforced masonry, and natural stone without requiring the fuel management and starting procedures associated with petrol equipment.
Metal Fabrication
Metal fabricators utilize the GA9020 for cutting through thick metal sections, removing excess material, and smoothing rough surfaces in steel and aluminum fabrication. The 230mm wheel diameter enables deep cuts through structural steel sections, thick plate materials, and large-diameter pipe. The powerful motor maintains cutting speed when working through materials that would slow or stall less robust grinders, improving productivity in production fabrication environments.
Surface Grinding and Preparation
The GA9020 performs heavy-duty surface grinding for removing mill scale, rust, old coatings, and weld spatter from steel structures and fabrications. The large wheel diameter provides substantial surface contact area for rapid material removal over large surface areas. When fitted with appropriate grinding wheels, the tool prepares surfaces for welding, coating application, or final finishing, with the anti-dust construction maintaining reliable operation despite the substantial debris generated during grinding operations.
Concrete and Masonry Work
Masons and concrete contractors employ the GA9020 with diamond grinding wheels for smoothing concrete surfaces, removing form marks, and leveling uneven concrete. The tool handles concrete cutting applications including creating control joints, cutting openings for services, and trimming concrete components to fit. The grinder's power enables efficient work through reinforced concrete where embedded reinforcing steel must be cut alongside the concrete matrix.
Automotive and Equipment Maintenance
Automotive repair shops and equipment maintenance facilities utilize the GA9020 for cutting exhaust systems, removing rusted fasteners, grinding welds, and preparing surfaces for repair welding. The tool's combination of power and durability suits the demanding conditions of maintenance work where tools encounter diverse materials and must operate reliably despite exposure to oils, coolants, and other automotive fluids. The 230mm wheel capacity accommodates the larger cutting and grinding wheels preferred for heavy vehicle and equipment maintenance.