The Makita 9557NB stands out in the crowded angle grinder market with its impressive power and affordable price tag under $100.
This tool’s 7.5 Amp motor delivers 11,000 RPM, but its capabilities go beyond raw power. Our hands-on review revealed the tool’s Labyrinth Construction that protects against dust and debris effectively.
Our extensive testing showed several overlooked features of this angle grinder. The gear housing rotates at 90-degree intervals – a versatility that sets it apart from competitors.
Professionals and DIY enthusiasts will appreciate this tool’s hidden capabilities and real-life performance. Let us help you decide if this angle grinder belongs in your workshop.
Makita 9557NB Angle Grinder: Specs That Matter
Let’s dig deeper into the technical specifications that make the Makita 9557NB stand out from other angle grinders in its class. Some features define this tool’s performance and durability beyond the simple specs.
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The 7.5 AMP motor delivers up to 11,000 RPM, providing strong and consistent performance.
Its compact build, featuring a 2-1/2″ diameter barrel and a weight of just 4.5 lbs., makes it comfortable to handle.
A zig-zag protective coating covers the armature, keeping dust and debris out to extend the tool’s lifespan.
Motor: 7.5 Amp, 11,000 RPM Output
The life-blood of the Makita 9557NB’s performance lies in its reliable 7.5 Amp motor that produces an impressive 11,000 RPM. This high-output power comes in a surprisingly compact package at only 3.5 pounds. The 9557NB offers much more power than Makita’s 9553NB and 9554NB models, which contain only 6.0 AMP motors.
This power-to-weight ratio gives you excellent handling without losing any grinding capability. The motor keeps its speed under load better than many competitors in the same price range and works well with all types of materials.
The motor’s thicker coil wires help it stay cooler and last longer. Makita’s engineers designed it this way to balance power with sustainability.
You’ll find a conveniently located switch on top of the motor housing that lets the tool handle both AC and DC power. This makes the tool more useful in different work settings.
Build Quality: Labyrinth Construction and Dust Protection
The Makita 9557NB lasts so long because of its innovative labyrinth construction. This design uses a complex set of channels that keep dust and debris away from both the motor and bearings.
The zigzag varnish coating on the armature stands out as a key protective feature. This special protective layer creates a barrier when rotating and keeps dust particles from getting into the motor’s internal parts. The zigzag pattern works better than regular varnish and shields against dust – the biggest enemy of power tools.
The grinder comes with dust-proof bearings and an all ball-bearing design that make it last much longer. A metal gear housing adds extra protection from impacts and daily wear.
So all these protective elements work together to fix the usual problems in angle grinders. This complete dust protection really helps when you’re cutting materials like concrete or masonry that create lots of debris.
Makita’s official documentation shows this construction method makes the tool last longer. This makes it worth the money, even though it’s already priced well for what you get.
Hidden Features Most Users Overlook
The Makita 9557NB packs more than just raw power and durability. This tool comes with clever design features that most casual users might miss. These hidden capabilities improve its versatility and make it much more user-friendly.
Rotatable Gear Housing: 90° Adjustability
The Makita 9557NB stands out from its competitors with its rotatable gear housing that can be positioned every 90 degrees. This smart design lets me adapt the tool quickly for different grinding angles without changing my grip or position.
The adjustable housing is a great way to get better results when working in tight spots or making complex cuts. To cite an instance, grinding on vertical surfaces or overhead becomes easier as I can rotate the housing instead of twisting my wrist awkwardly.
The gear housing’s quality really shines through. Built tough with premium materials, it keeps the internal gears safe while running smoothly even during heavy-duty work.
Compact Body Design for Tight Spaces
The 9557NB sports a slim design with a barrel grip measuring only 2-1/2 inches in diameter. This compact profile and light weight (just 4.5 pounds) makes it easy to handle in small spaces.
The compact body really helps when I’m working between joists, inside cabinets, or on cars where bigger grinders just don’t fit. Its intuitive design gives me a comfortable grip and better control, so my hands don’t tire out during long jobs.
This grinder’s sleek shape lets me work with precision while still delivering the full power of its 7.5 AMP motor.
Paddle Switch Safety Lock Mechanism
The slide switch with lock-on feature adds another clever touch to the design. This mechanism lets me keep grinding without holding down the trigger – a real help during long grinding sessions.
The switch placement deserves special mention. It sits right where my thumb naturally falls, making the tool safer and more comfortable to use.
The AC/DC compatibility switch adds extra flexibility when power options are limited. You might not notice this feature right away, but it proves invaluable in certain work situations.
Real-World Testing: What We Found After 30 Days
We put the Makita 9557NB through rigorous real-life testing for 30 days. The grinder faced challenges beyond typical usage scenarios to review its actual capabilities beyond what manufacturers claim.
Cutting and Grinding Performance on Steel and Aluminum
The 7.5 Amp motor with 11,000 RPM output worked amazingly well with materials of all types. The 9557NB managed to keep consistent speed without substantial power loss while grinding 1/4 inch steel. The grinder struck an excellent balance between power and control.
Key performance observations:
- Steel cutting stayed precise with minimal kickback
- Aluminum grinding produced clean results with less clogging than expected
- The grinder excelled at cutting exhaust pipes and grinding down weld joints
The compact size provides an excellent middle ground for all-purpose situations, though it’s nowhere near as powerful as larger professional models. Extended cutting sessions became easier with the small 2-1/2 inch diameter barrel grip that gave exceptional control.
Makita 9557NB Change Blade Process: Quick and Tool-Free
The push-button spindle lock made blade changes a breeze. Users can swap wheels quickly without searching for extra tools. The process starts by pressing the lock button, followed by using the included wrench to loosen the lock nut.
Standard wheels fit perfectly on the spindle thread (5/8″ – 11 UNC), making replacements easy to find. The well-designed flange system made wheel changes smooth and consistent throughout our testing.
Noise and Vibration Levels During Extended Use
The Makita 9557NB produces 86 dB(A) of noise, matching other tools in its class. The sound stayed consistent without developing any concerning mechanical noises that often plague lower-quality grinders.
Users will notice the vibration level of 7.5 m/s² during longer grinding sessions. The small-circumference barrel grip helped reduce hand fatigue. Makita’s anti-vibration side handles substantially reduce operator discomfort for professionals who plan extensive use.
The grinder’s labyrinth construction blocked dust effectively over our 30-day test period. Performance stayed consistent without the grinding noise that usually develops in well-used tools.
Maintenance and Parts: What You Need to Know
Your Makita 9557NB will last much longer with proper maintenance. Our extensive testing revealed several critical components and maintenance procedures that need attention.
Makita 9557NB Parts Diagram: Key Components Explained
A good grasp of the parts diagram helps you fix problems quickly. The Makita 9557NB has 56 individual components. Here are the most important parts you should know about:
The spiral bevel gears (parts #227541-3 and #227505-7) move power from the motor to the spindle. These gears sit protected by the labyrinth construction and rarely break unless you put them under extreme stress.
The armature assembly (part #515611-3, $31.56) sits at the core and has bearings and fan components. This assembly works alongside the field coil (part #621706-3) to create rotational force.
The spindle assembly links to the grinding wheel through the inner flange (part #224399-1, $15.32) and lock nut (part #193465-4, $16.66). You should check these components regularly for signs of wear.
Brush Replacement and Internal Access
Carbon brushes (part #CB325, approximately $6.19) need replacement after 80-100 hours of use. Watch out for these signs of wear:
- Excessive sparking from motor vents
- Inconsistent power during operation
- The tool struggles to start
Start by unplugging the grinder to replace brushes. Remove the brush holder caps (part #643760-7) with a flathead screwdriver. Take out worn brushes and put in new ones. Make sure they line up correctly.
The tool’s manual states clearly: “Always be sure that the tool is switched off and unplugged before attempting to perform inspection or maintenance”. Clean air vents often by removing any blockages.
Where to Find Makita 9557NB Parts Online
Replacement parts are accessible to more people thanks to the tool’s popularity. Several reliable sources stock what you need:
PartSelect.com and eReplacementParts.com carry most common components, including switches ($15.52), inner flanges, and carbon brushes. Both sites offer detailed repair guides with step-by-step instructions.
Makita’s official service centers guarantee authentic parts. The manual emphasizes: “To maintain product SAFETY and RELIABILITY, repairs… should be performed by Makita Authorized or Factory Service Centers, always using Makita replacement parts”.
Check your parts diagram for the exact part number before buying anything to ensure it fits your model.
Conclusion
Thorough testing and analysis shows the Makita 9557NB is a capable angle grinder that performs way beyond its sub-$100 price point. Its powerful 7.5 Amp motor and innovative labyrinth construction make it a reliable workhorse. Both professionals and DIY enthusiasts will find it useful.
We found some hidden features that add substantial value to daily operations. The 90-degree rotatable gear housing and compact barrel grip stand out. During our 30-day testing period, the grinder managed to keep consistent performance on different materials. It showed no signs of wear or dust infiltration.
The 9557NB hits the sweet spot between performance and portability, though some users might want more power for heavy-duty industrial work. Its straightforward maintenance and easy-to-find replacement parts definitely make it a smart long-term investment.
Quality tools don’t always need premium price tags – the Makita 9557NB proves this point. It may not have all the features of pricier models, but it excels where it matters: reliable performance, durability, and user-friendly operation.
